Ingvild Odsbu

• Štěpánka, Ptáčková,; Skurtveit, Svetlana Ondrasova; Roman, Gabrhelík,; Odsbu, Ingvild & Rolová, Gabriela (2026). Diagnostic pathways, healthcare utilization, and mortality in children and young people with early onset substance use disorders: a nationwide registry-based cohort study | Harm Reduction Journal | Springer Nature Link. Harm Reduction Journal. doi: 10.1186/s12954-026-01533-8. Full text in Research Archive Show summary

  Longitudinal, population-based evidence on the clinical profiles and mortality of youth with substance use disorders (SUDs) is limited, despite significant health and social risks. This study aimed to (1) characterize initial SUD diagnoses, demographic and healthcare profiles, and diagnostic trajectories, and (2) estimate all-cause and external-cause mortality relative to the general population. This nationwide cohort study included 22,449 individuals aged 6–24 newly diagnosed with SUD in the Czech Republic, 2015–2019. Sex-specific crude mortality rates (CMRs) and age-standardized mortality ratios (SMRs) were calculated for children (< 18 years) and young adults (18–29 years) to estimate mortality. The most common initial diagnoses were alcohol use disorders (55%), followed by polysubstance use (14%), and cannabis use disorders (11%). The mean age at first diagnosis was 18.7 years, lower for females (17.9) than males (19.1). Females were more often diagnosed with opioid, sedative/hypnotic, and stimulant use disorders, whereas males with cannabis and polysubstance use disorders (p < 0.001). During follow-up, 137 individuals (0.6%) died. All-cause and external-cause CMRs were 242.1 and 171.4 per 100,000 person-years, both higher in males (1.9- and 2.6-fold). Excess mortality was observed in both age groups, with all-cause SMRs of 9.5 (95% CI 5.6–16.0) for children and 5.7 (4.8–6.8) for young adults; external-cause SMRs were 19.1 (10.8–33.6) and 6.6 (5.3–8.1), respectively. Early-onset SUD in clinical populations shows substantial sex differences and markedly elevated early, premature mortality. These findings underscore the need for early detection and targeted interventions for vulnerable youth.

• Orangzeb, Saima; Hartz, Ingeborg; Bakken, Inger Johanne Landsjøåsen; Odsbu, Ingvild; Furu, Kari & Skurtveit, Svetlana Ondrasova [Show all 9 contributors for this article] (2026). Incidence of ADHD diagnoses and medication initiation among children and adolescents in Norway from 2016-2024. European Child and Adolescent Psychiatry. ISSN 1018-8827. doi: 10.1007/s00787-026-03116-1. Full text in Research Archive Show summary

  Global trends show an increase in ADHD diagnoses and medication use. This study aimed to describe the incidence of ADHD among children and adolescents in Norway from 2016 to 2024, and to investigate sociodemographic factors associated with treatment initiation among newly diagnosed individuals. This nationwide longitudinal study used data from Norwegian health registers, including all incident ADHD cases (first diagnosis or medication) at ages 3–17 years between 2016 and 2024. Incidence rates were calculated per 1,000 individuals along with proportion initiating medication 0–3 months and 4–12 months post diagnosis. Logistic regression models were used to assess factors associated with initiation. The overall incidence of ADHD more than doubled between 2016 and 2024 (from 4.4 to 9.0 per 1,000), with 52,149 incident ADHD cases. The most pronounced increase was observed among adolescent females (14–17 years), where incidence rose from 3.1 to 11.4 per 1,000. Among 38,749 individuals diagnosed between 2016 and 2023, the proportion initiating medication within one year of diagnosis increased from 72.8% to 78.4%. Following a peak in 2021, proportion initiation within 0–3 months declined, while initiation at 4–12 months increased. Having a foreign-born parent was associated with lower odds, while older age at diagnosis and lower paternal education associated with higher odds of medication-initiation. This study documents a doubling in the incidence of ADHD diagnoses among children in Norway, and an even stronger increase among adolescent females. Medication initiation increased slightly but evolved toward a delayed approach. Sociodemographic factors, especially age at diagnosis, parental region of birth and father’s education influence medication-initiation.

• Tesli, Martin Steen; Hjellvik, Vidar; Lergenmuller, Simon; Hjell, Gabriela; Jangmo, Andreas & Haram, Marit [Show all 13 contributors for this article] (2026). Socioeconomic Position and Somatic Comorbidity in Mental Disorders. Acta Psychiatrica Scandinavica. ISSN 0001-690X. doi: 10.1111/acps.70113. Full text in Research Archive Show summary

  Introduction Individuals with mental disorders face an elevated risk for somatic noncommunicable diseases (NCD), such as cardiovascular disease (CVDs), chronic obstructive pulmonary disease (COPD), diabetes, and cancer. Low socioeconomic position (SEP) is linked to both mental disorders and somatic NCDs, but its role in this association remains unclear. Here, we provide a comprehensive overview of how associations between mental disorders and somatic NCDs vary by SEP indicators. Methods Data on all adult individuals resident in Norway from 01.01.2008 to 01.01.2010 (N = 3,589,719) were derived from a nationwide registry linkage including information on primary and secondary health care, dispensed drugs, causes of death, and socioeconomic factors. We assessed four broad types of mental disorders (psychotic, bipolar, depressive and anxiety disorders) and four categories of somatic NCDs (CVD, COPD, diabetes, cancer) diagnosed during follow-up from 01.01.2010 to 31.12.2020. Educational attainment and household income were used as SEP indicators, in addition to parental educational attainment. Cox regression models estimated hazard ratios for somatic NCDs among individuals with mental disorders compared to the general population, adjusting for and stratifying by SEP, sex, and age. Results All mental disorders were associated with an increased risk of somatic NCDs, strongest for COPD and weakest for cancer. Risk increased with disorder severity, with psychotic and bipolar disorders showing the strongest associations. Young adults with psychosis had a 4–5-fold increased risk of diabetes and COPD. Low SEP was associated with both mental disorders and somatic NCDs with moderate attenuating effects in their co-occurrence and little variation across SEP strata. Conclusion We found an increased risk of somatic NCDs in individuals with mental disorders and identified young adults with psychosis as a particularly vulnerable subgroup. Low SEP compounds this burden, underscoring the need for integrated mental and somatic healthcare strategies.

• Rolová, Gabriela; Skurtveit, Svetlana Ondrasova; Bukten, Anne; Odsbu, Ingvild & Eide, Desiree (2026). Factors associated with changes in opioid analgesic prescribing after opioid agonist treatment initiation: A nationwide registry cohort study. Drug and Alcohol Dependence Reports. 19, p. 100426–100426. doi: 10.1016/j.dadr.2026.100426. Full text in Research Archive
• Amundsen, Ellen Johanna; Skurtveit, Svetlana Ondrasova & Odsbu, Ingvild (2026). Risk and cause of overdose death after exposure to dispensed opioid analgesics. Scandinavian Journal of Public Health. ISSN 1403-4948. p. 1–9. doi: 10.1177/14034948261424666. Full text in Research Archive Show summary

  Aims: Overdose deaths have been increasing in parts of Europe, including Norway, where opioid analgesics have been the leading cause since 2016. This study quantifies the risk of overdose death following exposure to dispensed opioid analgesics, stratified by sex and age, and examines associated causes of death. Methods: Nationwide data from 2010 to 2018 on overdose deaths were obtained from the Norwegian Cause of Death Registry and linked with the Norwegian Prescription Database to identify prior opioid analgesic dispensations. Aggregated prescription data and population figures from Statistics Norway were also used. Results: From 2010 to 2018, 42% of individuals who died from an overdose had been dispensed opioid analgesics in the previous year. Among those dispensed strong opioid analgesics, the overdose death rate was low but exceeded the population death rate among men aged 20–49 and women aged 20–39 years. The rate was higher in men and remained stable over time. Opioids other than heroin or methadone were listed as the cause of death in 62% of cases with prior dispensed opioid analgesics, compared with 24% among those without. Conclusions: The risk of overdose deaths following exposure to strong opioid analgesics was low but higher than population death rates for men under 50 and women under 40 years. Preventive strategies based on risk markers such as sex, age and opioid analgesic strengths, combined with other known risk markers, can help guide safer prescription of opioid analgesics and reduce overdose death.

• Skurtveit, Svetlana Ondrasova; McDonald, Rebecca Silvia; Handal, Marte; Hamina, Aleksi; Clausen, Thomas & Odsbu, Ingvild (2025). A comparison between individuals who died of intentional versus accidental overdoses. Suicidologi. ISSN 1501-6994. 30(2), p. 4–19. doi: 10.5617/suicidologi.12703. Full text in Research Archive Show summary

  The aim of the study was to describe differences between deaths from intentional versus accidental overdoses in Norway. This data linkage study comprised six nationwide health- and population registers. During the study period from 2011 to 2019, a total of 1,818 deaths from accidental and 363 deaths from intentional overdoses were registered. Pharmaceutically available opioids were more often found in post-mortem blood samples among intentional overdose deaths compared to accidental overdoses (73.0% vs 36.0%). Decedents in the intentional overdose group were on average eight years older, more frequently women with higher education and previous suicide attempts compared to accidental overdoses. Intentional overdose deaths more frequently had a lifetime history of chronic pain, cancer, as well as depression in the year prior to death. In the 30-day period prior to their death, a larger proportion of individuals in the intentional overdose group were dispensed opioids (43.0 % vs 21.4 %) and/or enzodiazepines (51.5 % vs. 38.7 %) compared to accidental overdoses. Intentional overdose deaths typically involve prescribed medicines and are more common among older, more often female individuals with a history of somatic disorders. This knowledge needs to be integrated into new and targeted prevention interventions.

• Nestvold, Håkon Høydal; Haarr, Eirik; Hamina, Aleksi; Hjellvik, Vidar; Skurtveit, Svetlana Ondrasova & Odsbu, Ingvild (2025). Incidence of and Determinants for Substance Use Disorders Among Individuals With Long‐Term Prescription Opioid Use: A Population‐Based Cohort Study. Pharmacoepidemiology and Drug Safety. ISSN 1053-8569. 34(9). doi: 10.1002/pds.70212. Full text in Research Archive Show summary

  Purpose: To assess the incidence of substance use disorders (SUDs) after long‐term prescription opioid use (LTOU) and to identify socioeconomic and clinical risk factors associated with SUD among individuals with LTOU. Methods: Cohort study using linked nationwide registers (2011–2019). We identified 114 916 individuals who used opioids for more than 3 months (LTOU) without previous LTOU or SUD diagnosis. Outcomes were any incident SUD diagnosed in primary or secondary care (ICPC‐2: P15‐P16, P18‐P19; ICD‐10: F10‐F16, F18‐F19) and opioid use‐related disorders (OUD) diagnosed in secondary care (ICD‐10: F11). We calculated age‐ and sex‐stratified incidence rates (IR), incidence rate ratios (IRR) and age‐standardized incidence rates (ASIR). Adjusted hazard ratios (aHR) were calculated using Cox proportional hazards regression. Results: In total, 5.3% (6069/114916) were diagnosed with SUD (ASIR = 28.7 per 1000 person‐years), and males had higher IRs compared to females (IRR). Males had higher risk of SUD in both the younger (aHR = 1.59, 95% CI 1.47–1.72) and older (1.66, 1.54–1.78) age group. Low education (1.87, 1.66–2.11) and unemployment (1.26, 1.15–1.38) had the strongest association with SUD in the younger age group versus low income (1.37, 1.21–1.57) and living alone (1.53, 1.41–1.65) in the older age group. Previously diagnosed mental disorders and use of benzodiazepines‐ or benzodiazepine‐related drugs (BZDRs) were associated with SUD in both age groups (1.85, 1.71–2.01; 2.37, 2.18–2.57). Being male and having used BZDRs were the covariates strongest associated with OUD. Conclusions: Being male, young, having low socioeconomic status, previous mental disorders or BZDR use were associated with SUD diagnosis among individuals with LTOU.

• Pazzagli, Laura; Odsbu, Ingvild; Cesta, Carolyn E.; Bellocco, Rino; Lagerros, Ylva Trolle & Pasternak, Björn (2025). Longitudinal Trajectories of Antidiabetic Medication Adherence Over 5 Years From Treatment Initiation—A Swedish Nationwide Cohort Study. Clinical and Translational Science (CTS). ISSN 1752-8054. 18(3), p. 1–12. doi: 10.1111/cts.70174. Full text in Research Archive
• Samuelsen, Per-Jostein; Hjellvik, Vidar; Odsbu, Ingvild; Stubhaug, Audun; Skurtveit, Svetlana Ondrasova & Vambheim, Sara Magelssen (2025). Trends in Postoperative Opioid Use in Norway 2011-2018: A Nationwide Registry-Based Study. Basic & Clinical Pharmacology & Toxicology. ISSN 1742-7835. 136(6). doi: 10.1111/bcpt.70040. Full text in Research Archive Show summary

  Little is known about the overall trends in postoperative opioid use in a Nordic setting. We investigated the trends in Norway between 2011 and 2018. We linked the Norwegian Prescription Database, the Norwegian Patient Registry, the Cancer Registry of Norway and the Cause of Death Registry. Postoperative opioid use was defined as the first opioid dispensing per year within 14 days of a NOMESCO Classification of Surgical Procedure code. We excluded patients with cancer or opioid maintenance therapy. We calculated period prevalence (Norwegian population ≥ 15 years as the denominator), substance distribution, initial amount and proportion of long-acting formulations. Among 746 435 postoperative opioid users ≥ 15 years, the period prevalence increased from 27.0/1000 in 2011 to 30.0/1000 in 2018 (long-term use: 2.0 to 3.3/1000). Codeine was most frequent (67%) in 2011, while codeine and tramadol were equally dispensed (41% and 43%) in 2018; oxycodone increased from 3% to 12%. The initial amount increased for opioids as a group but declined for oxycodone (1236 morphine milligram equivalents [MME]/patient to 914 MME/patient) and tramadol (233 MME/patient to 219 MME/patient). Long-acting depot formulations increased from 5% to 12%. Over time, postoperative opioid use increased, with a shift toward more tramadol and oxycodone in lower initial amounts, and increased use of long-acting formulations.

• Rolová, Gabriela; Engeland, Anders; Pedersen, Line; Odsbu, Ingvild; Hamina, Aleksi & Skurtveit, Svetlana Ondrasova (2025). Mortality among patients with long-term prescription opioid use in Norway: A nationwide registry-based cohort study. Pain. ISSN 0304-3959. 166(11), p. e555–e562. doi: 10.1097/j.pain.0000000000003653. Full text in Research Archive Show summary

  The aim was to estimate all-cause and cause-specific mortality in long-term prescription opioid users compared to the general population. This nationwide registry–based cohort study used data of patients aged 15 to 69 years with no previous cancer diagnosis and a recorded episode of long-term opioid analgesics use (anatomical therapeutic chemical [ATC] group N02A; N = 116,006) in Norway between 2011 and 2019. Sex-specific crude mortality rates (CMR) and age-standardized mortality ratios (SMRs) were calculated for all-cause and cause-specific mortality, ie, natural and unnatural causes for the whole study population and for different age groups (15-34, 35-54, and 55-69 years). Overall, 4.6% (2491/54,535) of men and 2.7% (1680/61,471) of women died during the follow-up period. Crude mortality rates for all-cause mortality were 1194 and 724 deaths per 100,000 person-years (PY) in men and women, respectively. Men had higher CMRs across all causes, particularly unnatural causes (221 and 101 deaths per 100,000 PY in men and women, respectively). Patients with long-term opioid use had a 4 times higher all-cause mortality (SMR = 3.8 [95% CI = 3.6-3.9] in men and 3.7 [3.5-3.9] in women aged 15-69 years) compared to the general Norwegian population of the same age. Excess mortality was observed across all causes, particularly suicide, accidents, and accidental poisoning. Standardized mortality ratios decreased with age and were highest for the youngest age group (15-34 years), particularly among men. Long-term prescription opioid use is associated with an increased risk of death. Clinicians should weigh the risks of long-term opioid use against the benefits.

• Jonéus, Paulina; Pasternak, Björn; Odsbu, Ingvild; Cesta, Carolyn E.; Bellocco, Rino & Lagerros, Ylva Trolle [Show all 7 contributors for this article] (2025). Differential use of antidiabetic medication related to income, cohabitation and area of residence: a Swedish nationwide cohort study. Journal of Epidemiology and Community Health. ISSN 0143-005X. 79, p. 571–579. doi: 10.1136/jech-2024-223262. Full text in Research Archive
• Nakitanda, Aya Olivia; Pazzagli, Laura; Pasternak, Björn & Odsbu, Ingvild (2025). Factors associated with antibiotic use during pregnancy in Sweden: a population-based cohort study. BMC Pregnancy and Childbirth. 25, p. 1–10. doi: 10.1186/s12884-025-07736-4. Full text in Research Archive
• Rolová, Gabriela; Skurtveit, Svetlana Ondrasova; Handal, Marte; Kurita, Geana Paula; Lid, Torgeir Gilje & Odsbu, Ingvild [Show all 7 contributors for this article] (2025). Trends in opioid prescribing in Scandinavian countries from 2010 to 2023: Insights from multi-metric evaluation. British Journal of Clinical Pharmacology. ISSN 0306-5251. 91(12), p. 3341–3352. doi: 10.1002/bcp.70177. Full text in Research Archive Show summary

  Aims Monitoring opioid prescribing across different healthcare systems is essential to understanding population-level exposure and informing global health policies. This study examined opioid utilization in Scandinavian countries between 2010 and 2023 using multiple complementary metrics, addressing the limitations of single-metric comparisons. Methods A repeated cross-sectional study utilizing publicly available drug use statistics on opioid analgesics (ATC group N02A) dispensed in pharmacies from Denmark, Norway and Sweden. We assessed annual changes in utilization based on four metrics: 1-year prevalence (users/1000 inhabitants/year), defined daily doses (DDD)/1000 inhabitants/day (TID), morphine milligram equivalents (MMEs)/TID, and MMEs/user/year. Results Opioid use declined in Denmark and Sweden—in both 1-year user prevalence and volumes of MMEs—while stabilizing in Norway. Norway consistently had a higher and stable prevalence of opioid users. Denmark led in total amounts of MMEs dispensed, likely due to more frequent morphine and oxycodone use, whereas Norway ranked highest in DDDs. Denmark and Sweden showed increasing preference for “strong opioids”, while codeine-paracetamol and tramadol remained predominant in Norway. The prevalence of oxycodone users increased in Norway and Sweden, with Sweden having the highest prevalence of users but the lowest annual average volumes per user. Conclusions This study found major differences in total opioid use and substance-specific prescribing patterns, reflecting diverse pain management strategies across Scandinavia. Changing use patterns suggest evolving prescribing strategies and possible shifts in the target group for opioid pain therapy. In addition, metric-dependent variation underscores the need for using multiple complementary metrics to accurately interpret opioid utilization trends.

• Rolová, Gabriela; Skurtveit, Svetlana Ondrasova; Gabrhelik, Roman; Mravčík, Viktor & Odsbu, Ingvild (2024). Exploring dual diagnosis in opioid agonist treatment patients: a registry-linkage study in Czechia and Norway. Addiction science & clinical practice. ISSN 1940-0632. 19(37). doi: 10.1186/s13722-024-00467-5. Full text in Research Archive Show summary

  Background Knowledge of co-occurring mental disorders (termed ‘dual diagnosis’) among patients receiving opioid agonist treatment (OAT) is scarce. This study aimed (1) to estimate the prevalence and structure of dual diagnoses in two national cohorts of OAT patients and (2) to compare mental disorders between OAT patients and the general populations stratified on sex and standardized by age. Methods A registry-linkage study of OAT patients from Czechia (N = 4,280) and Norway (N = 11,389) during 2010– 2019 was conducted. Data on mental disorders (F00-F99; ICD-10) recorded in nationwide health registers were linked to the individuals registered in OAT. Dual diagnoses were defined as any mental disorder excluding substance use disorders (SUDs, F10-F19; ICD-10). Sex-specific age-standardized morbidity ratios (SMR) were calculated for 2019 to compare OAT patients and the general populations. Results The prevalence of dual diagnosis was 57.3% for Czechia and 78.3% for Norway. In Czechia, anxiety (31.1%) and personality disorders (25.7%) were the most prevalent, whereas anxiety (33.8%) and depression (20.8%) were the most prevalent in Norway. Large country-specific variations were observed, e.g., in ADHD (0.5% in Czechia, 15.8% in Norway), implying differences in screening and diagnostic practices. The SMR estimates for any mental disorders were 3.1 (females) and 5.1 (males) in Czechia and 5.6 (females) and 8.2 (males) in Norway. OAT females had a significantly higher prevalence of co-occurring mental disorders, whereas SMRs were higher in OAT males. In addition to opioid use disorder (OUD), other substance use disorders (SUDs) were frequently recorded in both countries. Conclusions Results indicate an excess of mental health problems in OAT patients compared to the general population of the same sex and age in both countries, requiring appropriate clinical attention. Country-specific differences may stem from variations in diagnostics and care, reporting to registers, OAT provision, or substance use patterns.

• Odsbu, Ingvild; Hjellvik, Vidar; Handal, Marte; Hamina, Aleksi; Clausen, Thomas & Lid, Torgeir Gilje [Show all 8 contributors for this article] (2024). Psykiske lidelser og plager ved vedvarende opioidbruk for langvarige ikke-kreftrelaterte smerter – en registerstudie. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 144(2), p. 1–15. doi: 10.4045/tidsskr.23.0414. Full text in Research Archive Show summary

  Bakgrunn Kunnskap om psykiske lidelser blant pasienter med vedvarende opioidbruk for behandling av langvarige ikke-kreftrelaterte smerter er viktig, da psykiske lidelser og plager kan bidra til å forsterke eller vedlikeholde smerte og påvirke evnen til å håndtere egen sykdom. Vi har undersøkt forekomst av psykiske lidelser og plager, inkludert rusmiddellidelser, hos pasienter med vedvarende opioidbruk i 2019. Materiale og metode Personer ≥ 18 år med vedvarende opioidbruk og personer ≥ 18 år med minst én registrert psykisk lidelse i spesialisthelsetjenesten i 2019 ble inkludert. Data ble hentet fra nasjonale helseregistre. Pasienter som fikk opioider for langvarige smerter på blå resept ble sammenlignet med dem som fikk opioider utelukkende på hvit resept. Resultater Forekomsten av psykiske lidelser og plager var 34 % blant 14 403 personer som fikk opioidene forskrevet på blå resept, og 42 % blant 38 001 personer som fikk opioidene på hvit resept. Dette tilsvarer 2–3 ganger økt forekomst sammenlignet med den generelle befolkningen. Det var spesielt høyere forekomst av angstlidelser og rusmiddellidelser. Det var høyest forekomst av psykiske lidelser og plager i aldersgruppen 18–44 år (49–55 %). Fortolkning Blant pasienter med vedvarende opioidbruk var det en stor andel med psykiske lidelser og plager, som er kjente risikofaktorer for å utvikle problematisk opioidbruk og avhengighetssyndrom. HOVEDFUNN Forekomst av diagnostiserte psykiske lidelser og plager blant pasienter med vedvarende opioidbehandling av langvarige ikke-kreftrelaterte smerter i 2019 var høyest i den yngste aldersgruppen (18–44 år) og blant dem som fikk opioider utelukkende på hvit resept. Pasienter med vedvarende opioidbruk hadde 2–3 ganger høyere forekomst av psykiske lidelser, inkludert rusmiddellidelser, diagnostisert i spesialisthelsetjenesten sammenlignet med den generelle befolkningen. Rusmiddellidelser var hyppigst blant unge menn.

• Nøst, Torunn Hatlen; Skurtveit, Svetlana Ondrasova; Odsbu, Ingvild; Pedersen, Line; Borchgrevink, Petter Christian & Handal, Marte (2024). Prevalence of substance use disorder diagnoses in patients with chronic pain receiving reimbursed opioids: An epidemiological study of four Norwegian health registries. Scandinavian Journal of Pain. ISSN 1877-8860. 24(1), p. 1–9. doi: 10.1515/sjpain-2024-0059. Full text in Research Archive Show summary

  Objectives Since 2008, patients have had access to reimbursed analgesics, including opioids, for chronic pain in Norway. There is a need for knowledge on the occurrence and trends over time of substance use disorder (SUD) diagnoses among patients who receive reimbursed opioids for chronic pain. The primary aim of this study was to investigate the prevalence of SUD diagnoses in patients with chronic pain using reimbursed opioids from 2010 to 2019 in Norway. The secondary aim was to investigate the prevalence of other mental health diagnoses among those receiving reimbursed opioids in the subgroups with and without SUD diagnoses. Methods A cross-sectional design utilising data from four Norwegian nationwide registries. Results The annual number of individuals with SUD diagnoses increased from 377 to 932 from 2010 to 2019, while the annual prevalence of individuals with SUD remained relatively stable at around 5%. There was a higher prevalence for all categories of other mental health diagnoses among individuals with a SUD diagnosis, compared to those without a SUD diagnosis. Conclusion The prevalence of SUD diagnoses was low in the population using reimbursed opioids for chronic pain in Norway, but the number of patients increased in the study period because the number of individuals receiving reimbursed opioids increased. Patients with a SUD used on average twice the daily doses of opioids compared to patients without a SUD. They were also more likely to have an additional mental health diagnosis.

• Ørnskov, Mark Puch; Kurita, Geana Paula; Herling, Suzanne Forsyth; Sjøgren, Per; Skurtveit, Svetlana Ondrasova & Odsbu, Ingvild [Show all 8 contributors for this article] (2024). Opioid use after surgical treatment in the Danish population—Protocol for a register-based cohort study. Acta Anaesthesiologica Scandinavica. ISSN 0001-5172. 68(10), p. 1565–1572. doi: 10.1111/aas.14506. Full text in Research Archive Show summary

  Background: Over the past 25 years, global opioid consumption has increased. Denmark ranks fifth in opioid use globally, exceeding other Scandinavian countries. Postsurgical pain is a common reason for opioid prescriptions, but opioid use patterns after patient discharge from the hospital are unclear. This study examines trends in opioid prescription among Danish surgical patients over a year. Methods: This register-based cohort study will use data from Danish governmental databases related to patients undergoing the 10 most frequent surgical procedures in 2018, excluding cancer-related and minor procedures. The primary outcome will be the dispensed postoperative opioid prescriptions at retail pharmacies over four quar- ters. Secondary analyses will include associations with sex, age, education attainment, and oral morphine equivalent quotient. Surgical treatments and diagnoses will be identified using NOMESCO procedure codes and ICD-10 codes. Opioids will be iden- tified by ATC codes N02A and R05DA04. Subjects will be classified as preoperative opioid consumers or non-opioid consumers based on opioid prescriptions redeemed in the 6 months before surgery. Discussion: The study will use extensive national register-based data, ensuring con- sistent data collection and enhancing the generalizability of the findings to similar healthcare systems. The study may identify high-risk populations for long-term opi- oids and provide information to support opioid prescribing guidelines and public health policies.

• Bachmann, Christian J; Scholle, Oliver; Bliddal, Mette; dosReis, Susan; Odsbu, Ingvild & Skurtveit, Svetlana [Show all 10 contributors for this article] (2024). Recognition and management of children and adolescents with conduct disorder: a real-world data study from four western countries. Child and Adolescent Psychiatry and Mental Health (CAPMH). 18(1). doi: 10.1186/s13034-024-00710-6. Full text in Research Archive
• Amundsen, Ellen Johanna; Odsbu, Ingvild; Skurtveit, Svetlana Ondrasova & Gjersing, Linn (2024). Patterns of filled prescriptions and the association with risk of drug-induced death. A population-based nested case-control register study. Pharmacoepidemiology and Drug Safety. ISSN 1053-8569. 33(2). doi: 10.1002/pds.5763. Full text in Research Archive Show summary

  Purpose: Opioid analgesics (OA) and other pharmaceuticals have been associated with drug-induced deaths. However, there is a lack of knowledge regarding patterns of use of these pharmaceuticals in the population and regarding such associations. We identify and describe subgroups of people with different patterns of filled prescriptions of OA and other relevant pharmaceuticals and examine associations with drug-induced deaths. In addition, we estimate the proportion of drug-induced deaths with a filled OA prescription and OA as cause of death. Methods: A Norwegian population-based nested case-control register study with cases (drug-induced deaths 2010–2018, N = 2388) and population controls matched for age, gender and year of inclusion (N = 21 465). Patterns of filled prescriptions for opioid analgesics (OA), benzodiazepines and benzodiazepine-related drugs, gabapentinoids, ADHD medication and antidepressants/antipsychotics were explored by k-means cluster analysis. Associations with drug-induced deaths were estimated by conditional logistic regression adjusted for sociodemographic characteristics. Overlap of filled OA prescriptions and OA as cause of death was estimated. Results: Five clusters were identified: ‘few prescriptions’, ‘weak OA’, ‘ADHD medication’, ‘sedative/psychiatric morbidity’ and ‘strong OA’. The ‘strong OA’ cluster had higher socioeconomic status compared to the other groupings. The risk of drug-induced death was also highest in this cluster (OR = 35.5; CI 25.6–49.3) and, for 68% (CI 64–73) of cases, filled prescriptions for OA was indicated as the underlying cause of death. Conclusions: The cluster analysis identified a subgroup with filled prescriptions of OA and other pharmaceuticals and a higher socioeconomic status than othersubgroups. This subgroup had a high risk of drug-induced death that needs to be addressed.

• Nakitanda, Aya Olivia; Odsbu, Ingvild; Cesta, Carolyn E.; Pazzagli, Laura & Pasternak, Björn (2024). First Trimester Tetracycline Exposure and Risk of Major Congenital Malformations. JAMA Network Open. 7(11). doi: 10.1001/jamanetworkopen.2024.45055. Full text in Research Archive
• Nestvold, Håkon Høydal; Skurtveit, Svetlana Ondrasova; Hamina, Aleksi; Hjellvik, Vidar & Odsbu, Ingvild (2024). The risk of long-term opioid use among immigrants: a national registry-linkage study. Scandinavian Journal of Public Health. ISSN 1403-4948. doi: 10.1177/14034948241266744. Full text in Research Archive Show summary

  Aims: We aimed to investigate the association between being an immigrant and long-term prescription opioid use in Norway in 2010–2019. Methods: Nested case–control study. The cases were all persons 18 years of age or older with long-term opioid use – that is, the use of prescription opioids longer than 3 months (N=215,642). Cases were matched to four controls who filled at least one opioid prescription, but never developed long-term opioid use in the study period (N=862,568) on sex, age and year of starting long-term/short-term opioid use. Being an immigrant was defined as being born outside of Norway to two foreign-born parents and four foreign-born grandparents. Adjusting for socioeconomic variables and clinical confounders, analyses were stratified on three age groups (18-44 years, 45-67 years and ⩾68 years). Results: For the youngest age group, being an immigrant was inversely associated with long-term opioid use (adjusted odds ratio 0.75; 95% confidence interval [0.72–0.77]) compared with being native-born people. For this age group, the odds ratio differed between people born in Africa (0.56 [0.52–0.62]), Central or South America (0.70 [0.62–0.79]), Europe outside the European Union (EU) (0.71 [0.65–0.77]), Asia including Turkey (0.80 [0.77–0.84]) and EU/European Economic Area (EEA) (0.81 [0.77–0.85]). For the middle age group, increased odds were found for immigrants versus natives (1.05 [1.02–1.08]) in particular for those born in North America (1.26 [1.13–1.40]) and the EU/EEA (1.13 [1.09–1.18]). There was no association in the oldest group. Conclusions: Compared with native-born people, immigrants had lower odds of long-term opioid use among younger adults, higher odds among middle-aged and similar odds among older adults.

• Odsbu, Ingvild; Hamina, Aleksi; Hjellvik, Vidar; Handal, Marte; Haram, Marit & Tesli, Martin Steen [Show all 8 contributors for this article] (2024). Initiation of Antipsychotics During the First Year After First-Episode Psychosis: A Population-Based Study. Acta Psychiatrica Scandinavica. ISSN 0001-690X. doi: 10.1111/acps.13776. Full text in Research Archive Show summary

  Background Antipsychotics are recommended after first-episode psychosis. Knowledge on the current use patterns in real-world settings is thus important to inform clinical practice. We aimed to describe antipsychotic initiation during 1 year after first-episode psychosis and its associated factors. Methods Population-based cohort study using linked nationwide health and population registers from Norway. The study population comprised 8052 persons aged 16–45 years with first-episode psychosis diagnosed in secondary care (ICD-10 F20, F22–F29) in the period 2011–2019. Initiation of antipsychotic use was defined as being dispensed antipsychotics (ATC N05A, excl. lithium) at least once from −90 to +365 days from secondary care diagnosis of first-episode psychosis. Antipsychotic polypharmacy during follow-up was defined as having at least 90 days with overlapping drug use periods modeled using the Prescriptions to Drug Use Periods method. Adjusted risk ratios (aRRs) with 95% confidence intervals (CIs) for the association between socioeconomic and clinical factors and initiation of antipsychotic use were calculated using modified Poisson regression. Results In total, 4413 persons (54.8%) initiated antipsychotic use after first-episode psychosis with proportions ranging from 45.5% in 2012 to 62.1% in 2019. Oral formulations of olanzapine (34.9%), quetiapine (21.2%), and aripiprazole (11.6%) were most common at initiation, whereas long-acting injectables (LAIs) and clozapine were rarely used. Among the initiators, 13.8% started a polypharmacy period lasting more than 90 days. Factors associated with antipsychotic initiation were lower age (aRR 1.14, 95% CI 1.08–1.21; 26–35 years vs. 36–45 years), higher education (1.11, 1.05–1.18), being employed (1.04, 1.00–1.09), being hospitalized (1.13, 1.09–1.18), being diagnosed late in the study period (1.16, 1.11–1.22; 2017–2019 vs. 2011–2013), or with previously diagnosed bipolar disorder, depression, or anxiety disorders. Conclusions The antipsychotic use pattern is largely within the current clinical guideline. Primary non-compliance and disease severity may explain the socioeconomic and clinical differences related to initiation of antipsychotic use.

• Hartz, Ingeborg; Madsstuen, Nils Henry Haugen; Andersen, Per Normann; Handal, Marte & Odsbu, Ingvild (2024). Nationwide trends in the use of ADHD medications in the period 2006–2022: a study from the Norwegian prescription database. BMC Psychiatry. 24(1). doi: 10.1186/s12888-024-06199-9. Full text in Research Archive Show summary

  Background The use of medication for Attention-Deficit/Hyperactivity Disorder (ADHD) increased globally throughout the early 2000s. This study examine trends in prevalences and incidences of medication use in Norway from 2006 to 2022. Methods Data from the Norwegian Prescription Database were used to present one-year-prevalence and incidence rates of ADHD medication (ATC-group N06BA and C02AC02) for the overall population (ages 6–64) and within sex and age subgroups of children (ages 6–17) and adults (ages 18–64). Incident use was defined as the dispensing of medication, with no recorded use in the previous two calendar years. Results The overall prevalence of ADHD medication use in 6- to 64-year-olds increased from 5.2 to 19.4 per 1000 in the period, most pronounced from 2020 and onwards. While males experienced a nearly threefold increase in use (from 7.3 to 20.6 per 1000), the use among females increased almost sixfold during the study period (from 3.0 to 18.1 per 1000). Consequently, the male-to-female prevalence-ratio decreased from 2.4 to 1. Children exhibited a higher prevalence of use compared to adults throughout the period, although the largest relative increase was observed in adults, particularly in female adults. In children the male-to-female ratio decreased from 3.2 to 2.0, primarily due to an increasing use in 13–17-year-old females. Among adults, prevalences were similar across most age groups, with the highest rates observed among those aged 18–24, where female use exceeded male use by the end of the period. The male-to-female prevalence-ratio in adults decreased from 1.6 to 0.9 during the period. Parallel to prevalent use, overall incident use increased from 1.4 to 5.0 per 1000 during the period, with the most pronounced increase occurring from 2020 and onwards. From this point, incident use among females aged 13–17, 18–24, and 25–34, exceeded that of males. The male-to-female incidence-ratio decreased from 1.8 to 0.9. The overall incidence to prevalence ratio remained similar throughout the period, being 0.27 in 2006 and 0.25 in 2022. Conclusion A sustained increase in the prevalence of ADHD medication use was observed, with the most pronounced rise occurring among females and adults from 2020 and onwards. By 2022, the overall gender disparity in ADHD medication use had diminished, which should be considered in the context of a steep increase in incident use among adolescent and young adult females starting from 2020.

• Vambheim, Sara Magelssen; Hjellvik, Vidar; Odsbu, Ingvild; Skurtveit, Svetlana Ondrasova; Ekholdt, Christopher & Granan, Lars-Petter Ness [Show all 8 contributors for this article] (2024). Postoperative opioid use in Norway-a population-based observational study on patterns of long-term use. BMC Pharmacology and Toxicology. 25(1), p. 1–9. doi: 10.1186/s40360-024-00805-y. Full text in Research Archive Show summary

  Background The utilization patterns of opioid analgesics and the proportion of long-term opioid use after surgery in Norway is largely unknown. Methods This study aimed to estimate the proportion of one-year long-term prescription opioid use among all Norwegian postoperative opioid users. Complete data from central health registries (NPR, NorPD, Statistics Norway, CoDR) were linked via the personal identification number unique to all citizens. The study period was January 1st 2010 until December 31st 2019. Long-term opioid use was defined as at least two opioid dispensings within two subsequent 90-day periods, with a minimum average use of 10 MME/day for the first 90 days. Results The study population consisted of 693 495 post-operative opioid users (53.6% women), whereof 73.2% had not used opioids the year before surgery (new users). Among the postoperative opioid users, 3.8% were one-year long-term opioid users. The corresponding figures for new and previous opioid users were 0.4% and 13.1%, respectively. The highest proportions of long-term opioid use were found after transluminal endoscopy, eye surgery and assessments related to surgical procedures. In previous opioid users, the proportion of one-year long-term use was higher among women than men in all age groups, a difference that increased with age. Conclusions The proportion of postoperative long-term opioid use in Norway is generally low. We detected higher proportions of long-term opioid use after certain types of surgery, but our crude surgery definition warrants further examination. Previous opioid users pose a particular challenge in the management of postoperative pain. Trial registration The study used national health registry data from the period 2010–2019. A pre-registered analysis plan is available at Open Science Framework.

• Hamina, Aleksi; Odsbu, Ingvild; Hjellvik, Vidar; Lid, Torgeir Gilje; Clausen, Thomas & Skurtveit, Svetlana Ondrasova (2023). Fatal drug overdoses in individuals treated pharmacologically for chronic pain: a nationwide register-based study. British Journal of Anaesthesia. ISSN 0007-0912. 132(1), p. 86–95. doi: 10.1016/j.bja.2023.10.016. Full text in Research Archive Show summary

  Introduction Chronic pain patients may be at an increased risk for drug overdoses as a result of comorbid psychiatric disorders and treatment with risk-increasing prescription medications, such as opioids. We aimed to characterise fatal drug overdoses and investigate factors associated with the deaths among individuals who had been treated pharmacologically for chronic pain. Methods We included all individuals who received analgesics reimbursed for chronic pain in Norway during 2010–9 (n=569 047). Among this population, we identified all individuals with drug overdoses as cause of death (cases). Extracting data from national registries on diagnoses, filled prescriptions, and socioeconomic variables, we used a nested case-control design to compare the cases with age- and sex-matched controls from the study population. Results Overall, 623 (0.11%) individuals in the study population died of an overdose. Most, 66.8%, had overdosed accidentally, and 61.9% as a result of pharmaceutically available opioids. Compared with the controls (n=62 245), overdoses overall were associated strongly with substance use disorders (adjusted odds ratio 7.78 [95% confidence interval 6.20–9.77]), use of combinations of opioids, benzodiazepines and related drugs and gabapentinoids (4.60 [3.62–5.85]), previous poisoning with pharmaceuticals (2.78 [2.20–3.51]), and with living alone the last year of life (2.11 [1.75–2.54]). Intentional overdoses had a stronger association with previous poisonings with pharmaceuticals whereas accidental overdoses were strongly associated with substance use disorders. Conclusions This study shows the need for better identification of overdose and suicide risk in individuals treated for chronic pain. Extra caution is needed when treating complex comorbid disorders, especially with overdose risk-increasing medications.

• Eide, Desiree; Mcdonald, Rebecca Silvia; Hamina, Aleksi; Clausen, Thomas; Odsbu, Ingvild & Skurtveit, Svetlana Ondrasova (2023). Prescription high-risk polysubstance use among opioid maintenance treatment patients. International journal of drug policy. ISSN 0955-3959. doi: 10.1016/j.drugpo.2023.104196. Full text in Research Archive Show summary

  Background Among individuals receiving buprenorphine or methadone as opioid maintenance treatment (OMT), concomitant use of other central nervous system depressants, including prescription drugs, can increase risk of overdose. We aimed to 1) determine the prevalence of use of high-risk prescription drugs (opioid analgesics, benzodiazepines, benzodiazepine-related drugs, and gabapentinoids) among OMT patients, 2) calculate its associations with different mental health and pain-related diagnoses, and 3) compare prevalence of concomitant use with the general population. Methods A national sample comprising all individuals filling at least one prescription of OMT drugs in Norway in 2019 was formed. Healthcare registry data were linked to investigate high-risk prescription drug use and different diagnoses. We calculated one-year prevalence of use, amount dispensed in defined daily doses (DDDs), and the number of prescribers for the different high-risk prescription drugs. Logistic regression was used to determine associations (adjusted odds ratios; aOR, 95% confidence intervals (CIs)) between diagnoses and use. Prevalence of use was calculated both in the OMT patient sample and the general population. Results Among the OMT patient sample (n=7,299), 47.6% (n=3,476) filled prescriptions for benzodiazepines. For each high-risk prescription drug group, there was a median of 1-2 prescribers. Musculoskeletal diagnoses were the strongest factor for concomitant high-risk prescription drug use for both males (aOR 3.23, CI: 2.72-3.85) and females (aOR 3.07, CI: 2.42- 3.90). The 1-year prevalence of benzodiazepine use was 11.4 times higher for males and 7.1 times higher for females in OMT than the general population. The amount in DDDs was higher for every drug for OMT patients than the general population, particularly for benzodiazepines. Conclusions OMT patients frequently filled prescriptions for high-risk drugs, and in higher dosages than the general population. However, we found little evidence of ‘doctor shopping.’ Given that these prescription drugs carry overdose risk, particularly when combined with OMT drugs, our findings emphasize the continued need for education and caution to both prescribers and patients on their concomitant use with OMT.

• Rolova, Gabriela; Eide, Desiree; Gabrhelík, Roman; Odsbu, Ingvild; Clausen, Thomas & Skurtveit, Svetlana Ondrasova (2023). Gender differences in physical morbidity in opioid agonist treatment patients: population-based cohort studies from the Czech Republic and Norway. Substance Abuse Treatment, Prevention, and Policy. 18(1). doi: 10.1186/s13011-023-00557-8. Full text in Research Archive Show summary

  Background Physical diseases represent a significant burden for opioid agonist treatment (OAT) patients. This study described physical morbidity in two national cohorts of OAT patients focusing on gender differences. Methods This population-based cohort study linking multiple health registers investigated physical diseases (ICD-10) in patients receiving OAT in the Czech Republic (N = 4,280) and Norway (N = 11,389) during 2010–2019. Gender-stratified analysis was performed. Results Overall, we found a large burden of physical morbidity across gender groups in OAT patients. In the Czech Republic and Norway, women in OAT had a significantly higher prevalence of physical diseases across most diagnostic chapters, notably genitourinary diseases and neoplasms. Injuries/external causes and infectious/parasitic diseases were among the most common diseases in both women and men. Viral hepatitis accounted for over half of infectious morbidity in women and men in both cohorts. Conclusions Our findings support the need for early screening, detection, and treatment of diseases and conditions across organ systems and the integration of health promotion activities to reduce physical morbidity in OAT patients. The gender differences underline the need for a tailored approach to address specific medical conditions.

• Nestvold, Håkon Høydal; Skurtveit, Svetlana Ondrasova; Hamina, Aleksi; Hjellvik, Vidar & Odsbu, Ingvild (2023). Socioeconomic risk factors for long-term opioid use: A national registry-linkage study. European Journal of Pain. ISSN 1090-3801. 28(1), p. 95–104. doi: 10.1002/ejp.2163. Full text in Research Archive Show summary

  Abstract Background Opioid use has increased substantially as a treatment for chronic pain, although harms from long‐term opioid therapy outweigh the benefits. More knowledge about factors associated with long‐term opioid use is needed. We aimed to investigate the association between socioeconomic status and long‐term opioid use in the period 2010–2019. Methods This was a nested case–control study in which the cases were all persons ≥18 years with long‐term opioid use, that is use of opioids for more than 3 months ( N  = 215,642). Cases were matched on gender, age and index year (first long‐term use period) with four controls who filled at least one opioid prescription, but never developed long‐term opioid use in the study period ( N  = 862,568). We performed a logistic regression analysis adjusted for relevant confounders, stratified on age groups (18–67 years and 68 years and above). Results In the younger age group, long‐term opioid use was associated with low education (adjusted odds ratio, aOR = 1.54; 95% confidence interval, CI [1.51–1.57]), low income (1.33 [1.31–1.36]), being unemployed (1.40 [1.38–1.42]) and receiving disability pension (1.36 [1.33–1.38]). Weaker associations were found for living in a single‐person household or in a dense geographical area. Similar associations were found for the older age group. Conclusion We found that low socioeconomic status was associated with long‐term opioid use both among people in working age and older people. These results indicate a need for social and financial support for non‐pharmacological treatment of chronic pain among people with lower socioeconomic status. Significance This study shows that people with low socioeconomic status are at higher risk of developing long‐term opioid use. In the clinical setting, physicians should consider socioeconomic status when prescribing opioids for chronic pain. Non‐pharmacological treatment options funded by public health services should be prioritized to those with low socioeconomic status as long‐term opioid use in chronic pain patients is not recommended.

• Odsbu, Ingvild; Handal, Marte; Hjellvik, Vidar; Hernandez-Diaz, Sonia; Kieler, Helle & Nørgaard, Mette [Show all 9 contributors for this article] (2023). Prenatal opioid exposure and risk of asthma in childhood: a population-based study from Denmark, Norway, and Sweden. Frontiers in Pharmacology. 14, p. 1–12. doi: 10.3389/fphar.2023.1056192. Full text in Research Archive
• Nakitanda, Aya Olivia; Odsbu, Ingvild; Pasternak, Björn; Karlsson, Pär & Pazzagli, Laura (2023). Antibiotic use during pregnancy in Sweden: A nationwide utilization study covering 2007–2019. Acta Obstetricia et Gynecologica Scandinavica. ISSN 0001-6349. 103(3), p. 531–539. doi: 10.1111/aogs.14741. Full text in Research Archive
• Cohen, Jacqueline Mallory; Alvestad, Silje; Suarez, Elizabeth A.; Schaffer, Andrea; Selmer, Randi M. & Havard, Alys [Show all 21 contributors for this article] (2023). Comparative Risk of Major Congenital Malformations With Antiseizure Medication Combinations vs Valproate Monotherapy in Pregnancy. Neurology. ISSN 0028-3878. 102(2). doi: 10.1212/WNL.0000000000207996. Full text in Research Archive Show summary

  Background and Objectives Valproate should be avoided in pregnancy, but it is the most effective drug for generalized epilepsies. Alternative treatment may require combinations of other drugs. Our objectives were to describe first trimester use of antiseizure medication (ASM) combinations that are relevant alternatives to valproate and determine whether specific combinations were associated with a lower risk of major congenital malformations (MCM) compared with valproate monotherapy. Methods We conducted a population-based cohort study using linked national registers from Denmark, Finland, Iceland, Norway, and Sweden and administrative health care data from the United States and New South Wales, Australia. We described first trimester use of ASM combinations among pregnant people with epilepsy from 2000 to 2020. We compared the risk of MCM after first trimester exposure to ASM combinations vs valproate monotherapy and low-dose valproate plus lamotrigine or levetiracetam vs high-dose valproate (≥1,000 mg/d). We used log-binomial regression with propensity score weights to calculate adjusted risk ratios (aRRs) and 95% CIs for each dataset. Results were pooled using fixed-effects meta-analysis. Results Among 50,905 pregnancies in people with epilepsy identified from 7.8 million total pregnancies, 788 used lamotrigine and levetiracetam, 291 used lamotrigine and topiramate, 208 used levetiracetam and topiramate, 80 used lamotrigine and zonisamide, and 91 used levetiracetam and zonisamide. After excluding pregnancies with use of other ASMs, known teratogens, or a child diagnosed with MCM of infectious or genetic cause, we compared 587 exposed to lamotrigine-levetiracetam duotherapy and 186 exposed to lamotrigine-topiramate duotherapy with 1959 exposed to valproate monotherapy. Pooled aRRs were 0.41 (95% CI 0.24–0.69) and 1.26 (0.71–2.23), respectively. Duotherapy combinations containing low-dose valproate were infrequent, and comparisons with high-dose valproate monotherapy were inconclusive but suggested a lower risk for combination therapy. Other combinations were too rare for comparative safety analyses. Discussion Lamotrigine-levetiracetam duotherapy in first trimester was associated with a 60% lower risk of MCM than valproate monotherapy, while lamotrigine-topiramate was not associated with a reduced risk. Duotherapy with lamotrigine and levetiracetam may be favored to treat epilepsy in people with childbearing potential compared with valproate regarding MCM, but whether this combination is as effective as valproate remains to be determined. Classification of Evidence This study provides Class II evidence that in people with epilepsy treated in the first trimester of pregnancy, the risk of major congenital malformations is lower with lamotrigine-levetiracetam duotherapy than with valproate alone, but similar with lamotrigine-topiramate.

• Njotto, Lembris L.; Simin, Johanna; Fornes, Romina; Odsbu, Ingvild; Mussche, Isabelle & Callens, Steven [Show all 9 contributors for this article] (2023). Maternal and Early-Life Exposure to Antibiotics and the Risk of Autism and Attention-Deficit Hyperactivity Disorder in Childhood: a Swedish Population-Based Cohort Study. Drug Safety. ISSN 0114-5916. 46, p. 467–478. doi: 10.1007/s40264-023-01297-1. Full text in Research Archive
• Nakitanda, Aya O.; Kieler, Helle; Odsbu, Ingvild; Rhedin, Samuel; Almqvist, Catarina & Pasternak, Björn [Show all 7 contributors for this article] (2023). In-utero antibiotic exposure and subsequent infections in infancy: a register-based cohort study with sibling analysis. American Journal of Obstetrics & Gynecology MFM (AJOG MFM). 5(4), p. 1–10. doi: 10.1016/j.ajogmf.2023.100860. Full text in Research Archive
• Eide, Desiree; Skurtveit, Svetlana Ondrasova; Clausen, Thomas; Hesse, Morten; Mravčík, Viktor & Nechanská, Blanka [Show all 12 contributors for this article] (2023). Cause-Specific Mortality among Patients in Treatment for Opioid Use Disorder in Multiple Settings: A Prospective Comparative Cohort Study. European Addiction Research. ISSN 1022-6877. 29(4), p. 272–284. doi: 10.1159/000530822. Full text in Research Archive Show summary

  Introduction: Among people receiving current or previous opioid maintenance treatment (OMT), the leading cause of premature death is an opioid overdose. However, other causes of mortality remain high in this group. An understanding of causes of deaths across multiple settings can be useful in informing more comprehensive prevention responses. The aim of this study was to describe all non-overdose causes of death in three national cohorts (Czechia, Denmark, and Norway) among OMT patients and to explore associations of non-overdose mortality with age and gender. Methods: This prospective comparative cohort study used national mortality registry databases for OMT patients from Czechia (2000–2019), Denmark (2000–2018), and Norway (2010–2019). Crude mortality rates and age-standardized mortality rates (ASMRs) were calculated as deaths per 1,000 person years for cause-specific mortality. Results: In total, 29,486 patients were included, with 5,322 deaths recorded (18%). We found variations in causes of death among the cohorts and within gender and age groups. The leading non-overdose causes of death were accidents in Czechia and Denmark, and neoplasms in Norway. Cardiovascular deaths were highest in Czechia, particularly for women in OMT (ASMR 3.59 vs. 1.24 in Norway and 1.87 in Denmark). Conclusion: This study found high rates of preventable death among both genders and all age groups. Different demographic structures, variations in risk exposure, as well as variations in coding practices can explain the differences. The findings support increased efforts towards screening and preventative health initiatives among OMT patients specific to the demographic characteristics in different settings.

• Dudukina, Elena; Szépligeti, Szimonetta Komjáthiné; Karlsson, Pär; Asomaning, Kofi; Daltveit, Anne Kjersti Nesje & Hakkarainen, Katja [Show all 15 contributors for this article] (2023). Prenatal exposure to pregabalin, birth outcomes and neurodevelopment – a population-based cohort study in four Nordic countries. Drug Safety. ISSN 0114-5916. 46, p. 661–675. doi: 10.1007/s40264-023-01307-2. Full text in Research Archive Show summary

  Introduction Pregabalin is an antiepileptic drug frequently prescribed to pregnant women. Risks of adverse birth and postnatal neurodevelopmental outcomes following prenatal exposure to pregabalin are uncertain. Objective To investigate the association between prenatal exposure to pregabalin and the risks of adverse birth and postnatal neurodevelopmental outcomes. Methods This study was conducted using population-based registries in Denmark, Finland, Norway, and Sweden (2005–2016). We compared pregabalin exposure against no exposure to antiepileptics and against active comparators lamotrigine and duloxetine. We obtained pooled propensity score-adjusted estimates of association using fixed-effect and Mantel–Haenszel (MH) meta-analyses. Results The total number of pregabalin-exposed births was 325/666,139 (0.05%) in Denmark, 965/643,088 (0.15%) in Finland, 307/657,451 (0.05%) in Norway, and 1275/1,152,002 (0.11%) in Sweden. The adjusted prevalence ratios (aPRs) with 95% confidence interval (CI) following pregabalin exposure versus no exposure were 1.14 (0.98–1.34) for major congenital malformations and 1.72 (1.02–2.91) for stillbirth, which attenuated to 1.25 (0.74–2.11) in MH meta-analysis. For the remaining birth outcomes, the aPRs were close to or attenuated toward unity in analyses using active comparators. Adjusted hazard ratios (95% CI) contrasting prenatal pregabalin exposure versus no exposure were 1.29 (1.03–1.63) for ADHD and attenuated when using active comparators, 0.98 (0.67–1.42) for autism spectrum disorders, and 1.00 (0.78–1.29) for intellectual disability. Conclusions Prenatal exposure to pregabalin was not associated with low birth weight, preterm birth, small for gestational age, low Apgar score, microcephaly, autism spectrum disorders, or intellectual disability. On the basis of the upper value of the 95% confidence interval, increased risks greater than 1.8 were unlikely for any major congenital malformation and ADHD. For stillbirth and most groups of specific major congenital malformations, the estimates attenuated in MH meta-analysis.

• Gjerde, L. C.; Skurtveit, S.; Handal, M.; Nesvåg, R.; Clausen, T. & Lid, T. G. [Show all 9 contributors for this article] (2023). Mental disorder prevalence in chronic pain patients using opioid versus non-opioid analgesics: A registry-linkage study. European Journal of Pain. ISSN 1090-3801. 27(7), p. 884–895. doi: 10.1002/ejp.2121. Full text in Research Archive Show summary

  Background Chronic pain and mental disorders are leading causes of disability worldwide. Individuals with chronic pain are more likely to experience mental disorders compared to individuals without chronic pain, but large-scale estimates are lacking. We aimed to calculate overall prevalence of mental health diagnoses from primary and secondary care among individuals treated for chronic pain in 2019 and to compare prevalence among chronic pain patients receiving opioid versus non-opioid analgesics, according to age and gender. Methods It is a population-based cohort study. Linked data from nationwide health registers on dispensed drugs and diagnoses from primary (ICPC-2) and secondary (ICD-10) health care. Chronic pain patients were identified as all patients over 18 years of age filling at least one prescription of an analgesic reimbursed for non-malignant chronic pain in both 2018 and 2019 (N = 139,434, 69.3% women). Results Prevalence of any mental health diagnosis was 35.6% (95% confidence interval: 35.4%–35.9%) when sleep diagnoses were included and 29.0% (28.8%–29.3%) when excluded. The most prevalent diagnostic categories were sleep disorders (14% [13.8%–14.2%]), depressive and related disorders (10.1% [9.9%–10.2%]) and phobia and other anxiety disorders (5.7% [5.5%–5.8%]). Prevalence of most diagnostic categories was higher in the group using opioids compared to non-opioids. The group with the highest overall prevalence was young women (18–44 years) using opioids (50.1% [47.2%–53.0%]). Conclusions Mental health diagnoses are common in chronic pain patients receiving analgesics, particularly among young individuals and opioid users. The combination of opioid use and high psychiatric comorbidity suggests that prescribers should attend to mental health in addition to somatic pain. Significance This large-scale study with nation-wide registry data supports previous findings of high psychiatric burden in chronic pain patients. Opioid users had significantly higher prevalence of mental health diagnoses, regardless of age and gender compared to users of non-opioid analgesics. Opioid users with chronic pain therefore stand out as a particularly vulnerable group and should be followed up closely by their physician to ensure they receive sufficient care for both their mental and somatic symptoms.

• Hamina, Aleksi; Muller, Ashley Elizabeth; Clausen, Thomas; Skurtveit, Svetlana Ondrasova; Hesse, Morten & Tjagvad, Christian [Show all 11 contributors for this article] (2022). Prescription opioids among older adults: ten years of data across five countries. BMC Geriatrics. 22(429). doi: 10.1186/s12877-022-03125-0. Full text in Research Archive Show summary

  Background Opioid use has increased globally in the recent decade. Although pain remains a significant problem among older adults, susceptibility to opioid-related harms highlights the importance of careful opioid therapy monitoring on individual and societal levels. We aimed to describe the trends of prescription opioid utilisation among residents aged ≥65 in all Nordic countries during 2009–2018. Methods We conducted cross-sectional measurements of opioid utilisation in 2009–2018 from nationwide registers of dispensed drugs in Denmark, Finland, Iceland, Norway, and Sweden. The measures included annual opioid prevalence, defined daily doses (DDDs) per 1000 inhabitants per day (DIDs), and morphine milligram equivalents (MMEs) per user per day. Results From 2009 to 2018, an average of 808,584 of adults aged ≥65 used opioids yearly in all five countries; an average annual prevalence of 17.0%. During this time period, the prevalence decreased in Denmark, Norway, and Sweden due to declining codeine and/or tramadol use. Iceland had the highest opioid prevalence in 2009 (30.2%), increasing to 31.7% in 2018. In the same period, DIDs decreased in all five countries, and ranged from 28.3 in Finland to 58.5 in Denmark in 2009, and from 23.0 in Finland to 54.6 in Iceland in 2018. MMEs/user/day ranged from 4.4 in Iceland to 19.6 in Denmark in 2009, and from 4.6 in Iceland to 18.8 in Denmark in 2018. In Finland, Norway, and Sweden, MMEs/user/day increased from 2009 to 2018, mainly due to increasing oxycodone utilisation. Conclusions The stable or decreasing opioid utilisation prevalence among a majority of older adults across the Nordic countries coincides with an increase in treatment intensity in 2009–2018. We found large cross-national differences despite similarities across the countries’ cultures and healthcare systems. For the aged population, national efforts should be placed on improving pain management and monitoring future trends of especially oxycodone utilisation.

• Hamina, Aleksi; Odsbu, Ingvild; Borchgrevink, Petter Chr.; Chen, Li-Chia; Clausen, Thomas & Espnes, Ketil Arne [Show all 18 contributors for this article] (2022). Cohort Description: Preventing an Opioid Epidemic in Norway – Focusing on Treatment of Chronic Pain (POINT) – A National Registry-Based Study. Clinical Epidemiology. 14, p. 1477–1486. doi: 10.2147/CLEP.S382136. Full text in Research Archive Show summary

  Aim: The POINT project aims to provide evidence to optimise chronic pain management, prevent adverse consequences of opioids, and improve chronic pain patients’ pain relief, functional capacity, and quality of life. We describe the outline of the project and its work packages. More specifically, we describe a cohort of persons with chronic pain and a cohort of long-term opioid users identified from a national registry linkage. Data Sources: The project utilises data from nationwide healthcare and population registers in Norway. Using the Norwegian Prescription Database, we identified a cohort of persons who have been dispensed drugs reimbursed for chronic pain and a cohort of persons who used opioids long term from 2010 to 2019. Data from the Norwegian Registry for Primary Health Care and the Norwegian Patient Registry (2008– 2019), Cancer Registry (1990– 2018) Cause of Death Registry (2010– 2019) and demographic and socioeconomic registers from Statistics Norway (2010– 2019) were linked to the cohorts. Study Population: There were 568,869 participants with chronic pain. Sixty-three percent of the cohort was women, and the mean age was 57.1 years. There were 336,712 long-term opioid users (58.6% women; 60.9 years). In chronic pain and long-term opioid user cohorts, the most frequent musculoskeletal diagnosis was back pain diagnosed in primary care (27.6% and 30.7%). Psychiatric diagnoses were also common. Main Variables: Upcoming studies will utilise psychiatric and somatic diagnoses from the patient registers, drug use from the prescription register, causes of death, demographics, and socioeconomic status (eg, education, income, workability, immigrant status) as exposures or outcomes. Conclusion and Future Plans: The two cohorts have numerous pain-related diagnoses, especially in the musculoskeletal system, and noticeably frequent somatic and psychiatric morbidity. The POINT project also includes later work packages that explore prescriber and patient perspectives around safe and effective treatment of chronic pain.

• Cohen, Jacqueline Mallory; Alvestad, Silje; Cesta, Carolyn E.; Bjørk, Marte-Helene; Leinonen, Maarit & Nørgaard, Mette [Show all 18 contributors for this article] (2022). Comparative Safety of Antiseizure Medication Monotherapy for Major Malformations. Annals of Neurology. ISSN 0364-5134. doi: 10.1002/ana.26561. Full text in Research Archive Show summary

  Objective: This study was undertaken to examine the comparative safety of antiseizure medication (ASM) monotherapy in pregnancy with respect to risk of major congenital malformations (MCMs), overall and by MCM subtype. Methods: We conducted a population-based cohort study using national health register data from Denmark, Finland, Iceland, Norway, and Sweden (1996–2020). We compared pregnancies with first trimester exposure to lamotrigine monotherapy to ASM-unexposed, carbamazepine, valproate, oxcarbazepine, levetiracetam, and topiramate to lamotrigine monotherapy, and stratified monotherapy groups by dose. The outcome was nongenetic MCM and specific subtypes. We estimated adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) with log-binomial regression and propensity score weights. Results: There was a higher crude risk of any MCM in pregnancies exposed to lamotrigine monotherapy (n = 8,339) compared to ASM-unexposed pregnancies (n = 4,866,362), but not after confounder adjustment (aRR = 0.97, 95% CI = 0.87–1.08). Compared to lamotrigine, there was an increased risk of malformations associated with valproate (n = 2,031, aRR = 2.05, 95% CI = 1.70–2.46) and topiramate (n = 509, aRR = 1.81, 95% CI = 1.26–2.60), which increased in a dose-dependent manner. We found no differences in malformation risk for carbamazepine (n = 2,674, aRR = 0.91, 95% CI = 0.72–1.15), oxcarbazepine (n = 1,313, aRR = 1.09, 95% CI = 0.83–1.44), or levetiracetam (n = 1,040, aRR = 0.78, 95% CI = 0.53–1.13). Valproate was associated with several malformation subtypes, including nervous system, cardiac, oral clefts, clubfoot, and hypospadias, whereas lamotrigine and carbamazepine were not. Interpretation: Topiramate is associated with an increased risk of MCM similar to that associated with valproate, but lower doses may mitigate the risks for both drugs. Conversely, we found no increased risks for lamotrigine, carbamazepine, oxcarbazepine, or levetiracetam, which is reassuring.

• Skurtveit, Svetlana Ondrasova; Odsbu, Ingvild; Gjersing, Linn; Handal, Marte; Lid, Torgeir Gilje & Clausen, Thomas [Show all 7 contributors for this article] (2022). Individuals Dying of Overdoses Related to Pharmaceutical Opioids Differ from Individuals Dying of Overdoses Related to Other Substances: A Population-Based Register Study. European Addiction Research. ISSN 1022-6877. 28(6). doi: 10.1159/000526145. Full text in Research Archive Show summary

  Background: Pharmaceutical opioid (PO) overdose deaths have increased in many Western countries. There are indications that those dying from a PO overdose differ from those dying from other types of overdoses. These differences might pose a challenge as the majority of current preventive measures are tailored toward those with the characteristics of "conventional" overdose deaths. Objective: We investigated differences in the characteristics of persons who died from PO overdoses compared to all other overdoses. Material and methods: Using the Norwegian Cause of Death Registry, we retrieved information on overdoses classified according to ICD-10 and identified PO overdoses (T40.2; T40.4) and all other overdoses (T40.X; T43.6) in 2010-2019. By linking data from nationwide registers, we analyzed data on opioid dispensations and the history of mental and behavioral disorders. 1,224 persons were registered with PO overdoses and 1,432 persons with other overdoses. Results: Persons in the PO overdose group were older and were more frequently women (35.0% vs. 20.5%) than persons with other overdoses. They had a higher prevalence of chronic pain (35.8% vs. 13.2%), history of cancer (8.1% vs. 1.8%), filled prescriptions of analgetic opioids more frequently the month before death (38.8% vs. 12.0%), and used threefold higher doses of prescribed opioids compared to individuals in all other overdose group (66 vs. 26 oral morphine equivalents/day). In the PO overdose group, oxycodone and fentanyl were more frequently dispensed, while codeine was more frequently dispensed in the other overdose groups. A lower proportion of those in the PO overdose group had recorded diagnoses of substance use disorders, schizophrenia, and hyperkinetic disorder compared to the other overdose groups. Conclusion: Persons dying from overdoses on POs often differ from the population targeted by existing prevention strategies, as they are more frequently older women with chronic pain and using high doses of prescription opioids.

• Hamina, Aleksi; Hjellvik, Vidar; Handal, Marte; Odsbu, Ingvild; Clausen, Thomas & Skurtveit, Svetlana Ondrasova (2022). Describing long-term opioid use utilizing Nordic Prescription Registers - A Norwegian example. Basic & Clinical Pharmacology & Toxicology. ISSN 1742-7835. 130(4), p. 481–491. doi: 10.1111/bcpt.13706. Full text in Research Archive Show summary

  Previous studies have defined long-term opioid use in varying ways, decreasing comparability, reproducibility and clinical applicability of the research. Based on recommendations from recent systematic reviews, we aimed to develop a methodology to estimate the prevalence of use persisting more than three months utilizing one of the Nordic prescription registers. We used the Norwegian Prescription Register (NorPD) to extract data on all opioid dispensations between 1 January 2004 and 31 October 2019. New users of opioids (washout 365 days) were defined as long-term users if they fulfilled two criteria: (1) they had ≥2 dispensations of opioids, 91–180 days apart; (2) days 0–90 included ≥90 dispensed administration units (e.g., tablets) of opioids. Overall, there were 2,543,224 new users of opioids during the study period. Of these, 354,666 (13.9%) fulfilled the criteria for long-term opioid use at least once. Compared with those who did not fulfil the criteria (short-term users), long-term users were older, more likely women and used tramadol, oxycodone and buprenorphine more frequently as their first opioid. In conclusion, we found that 1/7 of opioid users continued use longer than 3 months. Future outcome research should identify the clinically most important dose requirements for long-term opioid use criteria.

• Nakitanda, Aya Olivia; Karlsson, Pär; Löfling, Lukas; Cesta, Carolyn E. & Odsbu, Ingvild (2022). Antimicrobial use in Sweden during the COVID-19 pandemic: prescription fill and inpatient care requisition patterns. BMC Infectious Diseases. 22(1). doi: 10.1186/s12879-022-07405-3. Full text in Research Archive
• Odsbu, Ingvild; Handal, Marte; Hjellvik, Vidar; Borchgrevink, Petter Chr.; Clausen, Thomas & Nesvåg, Ragnar [Show all 7 contributors for this article] (2022). Vedvarende bruk av opioider og samtidig bruk av andre vanedannende legemidler. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 142(3), p. 1–8. doi: 10.4045/tidsskr.21.0659. Full text in Research Archive Show summary

  BAKGRUNN<p> Vedvarende bruk av opioider kan ha uheldige konsekvenser. Vi har undersøkt vedvarende opioidbruk i pasientgruppersom fikk forskrevet opioider på ulike indikasjoner(langvarig smerte, palliativ behandling, andre (hvitresept)),samt gruppenessamtidige bruk av enkelte andre vanedannende legemidler.<p> MATERIALE OG METODE<p> <p>Personer med minst én utlevering av et opioid i Reseptregisteret i perioden 2011–19 ble inkludert. Vedvarende bruk i et kalenderår ble definertsom uthenting av > 180 definerte døgndoser eller > 4 500 mg orale morfinekvivalenterfordelt på minst tre kvartaler.<p> <p>RESULTATER Antall vedvarende opioidbrukere var 50 422 i 2011 og 59 996 i 2019 (10,1 % og 10,7 % av alle opioidbrukere). I perioden økte antalletsom fikk opioider på blå resept forlangvarige smerter, med 9 952 personer, men flertallet (n = 38 006, 63,3 %) fikk fortsa utlevert opioider utelukkende på hvitresept i 2019. Henholdsvis15 623 (41,1 %) og 14 881 (39,2 %) av de vedvarende opioidbrukerne som fikk utlevert opioider kun på hvitresept i 2019, fikk også utlevert benzodiazepiner og z-hypnotika samme år. Av de 23 967 vedvarende brukerne som også fikk utlevert benzodiazepiner, fikk 88 % utlevert opioider og benzodiazepiner på samme dag minst én gang i løpet av 2019.<p> <p>FORTOLKNING Vedvarende forskrivning av opioider på hvitresept og samtidig forskrivning av andre vanedannende legemidler kan tyde på uheldig bruk uten klarindikasjon.

• Pazzagli, Laura; Chacón, Silvia Segovia; Karampelias, Christos; Cohen, Jacqueline Mallory; Bröms, Gabriella & Kieler, Helle [Show all 10 contributors for this article] (2022). Association between folic acid use during pregnancy and gestational diabetes mellitus: Two population-based Nordic cohort studies. PLOS ONE. 17(8). doi: 10.1371/journal.pone.0272046. Full text in Research Archive Show summary

  Introduction Inconsistent results have been reported on the association between folic acid use in pregnancy and risk of GDM. The aim of this study was to estimate the association between folic acid use and GDM in two population-based Nordic cohorts. Material and methods Two cohort studies were conducted using data from the national population registers in Norway (2005–2018, n = 791,709) and Sweden (2006–2016, n = 1,112,817). Logistic regression was used to estimate the associations between GDM and self-reported folic acid use and prescribed folic acid use, compared to non-users, adjusting for covariates. To quantify how potential unmeasured confounders may affect the estimates, E-values were reported. An exposure misclassification bias analysis was also performed. Results In Norwegian and Swedish cohorts, adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for maternal self-reported folic acid use were 1.10 (1.06–1.14) and 0.89 (0.85–0.93), with E-values of 1.43 (1.31) and 1.50 (1.36), respectively. For prescribed folic acid use, ORs were 1.33 (1.15–1.53) and 1.56 (1.41–1.74), with E-values of 1.99 (1.57) and 2.49 (2.17), in Norway and Sweden respectively. Conclusions The slightly higher or lower odds for GDM in self-reported users of folic acid in Norway and Sweden respectively, are likely not of clinical relevance and recommendations for folic acid use in pregnancy should remain unchanged. The two Nordic cohorts showed different directions of the association between self-reported folic acid use and GDM, but based on bias analysis, exposure misclassification is an unlikely explanation since there may still be differences in prevalence of use and residual confounding. Prescribed folic acid is used by women with specific comorbidities and co-medications, which likely underlies the higher odds for GDM.

• Odsbu, Ingvild; Mahic, Milada; Skurtveit, Svetlana Ondrasova; Lund, Ingunn Olea & Handal, Marte (2021). An 11-year nationwide registry-linkage study of opioid maintenance treatment in pregnancy in Norway. Norsk Epidemiologi. ISSN 0803-2491. 29(1-2), p. 63–70. doi: 10.5324/nje.v29i1-2.4047. Full text in Research Archive Show summary

  Aim: We aimed to describe opioid maintenance treatment (OMT) to pregnant women in Norway and study the background characteristics of the pregnant women compared to the general population of pregnant women and to a previous clinical cohort study of OMT in pregnancy. Methods: Population-based cohort study with linked data from the Norwegian Medical Birth Registry, the Norwegian Prescription Database, the Norwegian Patient Registry, and Statistics Norway. The study population consisted of women giving birth between 2005-2015 in Norway. We defined OMT pregnancies as pregnancies where the woman was dispensed OMT medications (methadone, buprenorphine, or buprenorphine/ naloxone) at least once during pregnancy. Results: The study population consisted of 420,808 women with 645,440 pregnancies ending in a live birth in Norway in 2005-2015 (the general pregnant population). Of these, 261 women (0.6‰) had altogether 306 OMT pregnancies. The mean number of pregnancies was 28 OMT pregnancies per year and quite stable during the study period. Women with OMT pregnancies were older, smoked tobacco more frequently, had lower education, and fewer of them had a partner, compared to the general population of pregnant women. In most pregnancies, the women were treated with buprenorphine (n=183 (59.8%)), while in 120 (39.2%) pregnancies, the woman received methadone. From 2008, buprenorphine replaced methadone as the most frequently used drug. In only 38 (12.4%) pregnancies, OMT treatment was initiated in pregnancy. In 201 (66%) pregnancies, the woman used OMT medications in all trimesters. For these women, the mean amount of dispensed drug was 3.4 DDD/day (85 mg/day) in pregnancy for methadone and 1.9 DDD/day (15.2 mg/day) for buprenorphine. Conclusion: The number of OMT pregnancies per year has been low and stable in the period 2005-2015. Following Norwegian recommendations, there has been a shift from treatment with methadone towards buprenorphine. The women receiving OMT during pregnancy had more risk factors for adverse outcomes than the general pregnant population but were quite similar to the previous clinical cohort.

• Odsbu, Ingvild; Handal, Marte; Hjellvik, Vidar; Borchgrevink, Petter Chr.; Clausen, Thomas & Hamina, Aleksi [Show all 9 contributors for this article] (2021). Bruk av andre vanedannende legemidler blant opioidbrukere med langvarige smerter. Norsk Epidemiologi. ISSN 0803-2491. 29(1-2), p. 45–53. doi: 10.5324/nje.v29i1-2.4045. Full text in Research Archive Show summary

  Bakgrunn: Opioider for behandling av langvarige smerter kan forskrives på blå resept, men bør ikke brukes samtidig med andre vanedannende legemidler. Hensikt: Å undersøke bruk av opioider på blå resept i perioden 2009-2019, samt å studere bruk av andre vanedannende legemidler (benzodiazepiner og z-hypnotika) blant dem som fikk opioider på blå resept i 2019. Metode: Data ble hentet fra Reseptregisteret. En prevalent opioidbruker i 2019 ble definert som en person med minst én utlevering av et smertestillende opioid på blå resept for langvarige smerter også i 2018. Bruk av andre vanedannende legemidler ble definert som minst én utlevering av et annet vanedannende legemiddel i løpet av samme år. Resultater: Totalt 18 443 personer (67% kvinner) fikk utlevert opioider på blå resept i 2019, en økning fra 5 568 i 2009 via 10 693 i 2016 og 16 133 i 2017. Av de 18 443 var 14 202 (77%) prevalente opioidbrukere. Blant de prevalente brukerne fikk 88% utlevert 100 mg orale morfinekvivalenter (OMEQ) eller mindre per dag. Totalt fikk 54% av de prevalente opioidbrukerne utlevert minst ett annet vanedannende legemiddel i 2019. Z-hypnotika var oftest forekommende blant de som brukte 100 mg OMEQ eller mindre per dag, mens benzodiazepiner alene eller i kombinasjon med z-hypnotika dominerte blant opioidbrukerne som fikk utlevert mer enn 100 mg OMEQ per dag. Mengden utlevert av andre vanedannende legemidler økte med mengden opioider brukt per dag. En større andel kvinner enn menn fikk utlevert andre vanedannende legemidler i 2019. Konklusjon: Studien indikerer at bruk av andre vanedannende legemidler forekommer hos en stor andel av dem som får forskrevet opioider på blå resept. Dette er tegn på et uheldig forskrivningsmønster som bør studeres nærmere.

• Aas, Christer Frode; Vold, Jørn Henrik; Skurtveit, Svetlana; Odsbu, Ingvild; Chalabianloo, Fatemeh & Lim, Aaron G. [Show all 8 contributors for this article] (2020). Uptake and predictors of direct-acting antiviral treatment for hepatitis C among people receiving opioid agonist therapy in Sweden and Norway: a drug utilization study from 2014 to 2017. Substance Abuse Treatment, Prevention, and Policy. 15(1):44. doi: 10.1186/s13011-020-00286-2. Full text in Research Archive Show summary

  Background Treatment with direct-acting antiviral agents (DAAs) offers an opportunity to eliminate hepatitis C virus (HCV) endemic among people who inject drugs (PWID) and people enrolled in opioid agonist therapy (OAT) programs. The objective of this study was to estimate and to compare HCV treatment uptake after the introduction of DAAs among patients receiving OAT in Sweden and Norway. We also aimed to evaluate predictors of DAAs treatment among OAT patients in both countries. Methods This observational study was conducted with data from The Swedish Prescribed Drug Register and The Norwegian Prescription Database. We studied dispensed medications to calculate HCV treatment among OAT patients from 2014 to 2017 in Sweden and Norway. HCV prevalence was estimated from primary and secondary sources. Dispensations of medicines from different therapeutic areas, which served as proxy for co-morbidities in 2017, were conditionally adjusted for age, gender, and OAT medications. Logistic regression was used to evaluate these parameters. Results In total 3529 individuals were identified with dispensed OAT in the Swedish cohort and 7739 individuals in the Norwegian cohort. HCV treatment was utilized by 407 persons in Sweden and 920 in Norway during the study period. Annual HCV and DAA treatment uptake increased in both countries. The estimated cumulative HCV treatment uptake at the end of 2017 was 31% in Norway and 28% in Sweden. DAA treatment was associated with increased age (aOR 1.8; 95% CI 1.0–3.2) and the dispensation of drugs used for diabetes (aOR 3.2; 95% CI 1.8–5.7) in Sweden. In Norway, lipid modifying agents and antibacterials were associated with decreased odds (aOR 0.4; 95%CI 0.2–0.9, aOR 0.8; 95%CI 0.6–1.0). Conclusions An increase in DAA treatment and HCV treatment uptake was observed among Swedish and Norwegian OAT patients whilst introducing new direct-acting antiviral treatment regimens. However, more than two thirds of the OAT population in Norway and Sweden were untreated at the beginning of 2018. A further scale-up is crucial in order to control and eliminate the HCV endemic among OAT patients.

• Mahic, Milada; Hernandez-Diaz, Sonia; Wood, Mollie; Kieler, Helle; Odsbu, Ingvild & Nørgaard, Mette [Show all 11 contributors for this article] (2020). In utero opioid exposure and risk of infections in childhood: A multinational Nordic cohort study. Pharmacoepidemiology and Drug Safety. ISSN 1053-8569. 29(12), p. 1596–1604. doi: 10.1002/pds.5088. Full text in Research Archive
• Vold, Jørn Henrik; Aas, Christer Frode; Skurtveit, Svetlana; Odsbu, Ingvild; Chalabianloo, Fatemeh & Reutfors, Johan [Show all 9 contributors for this article] (2020). Potentially addictive drugs dispensing to patients receiving opioid agonist therapy: a register-based prospective cohort study in Norway and Sweden from 2015 to 2017. BMJ Open. 10(8). doi: 10.1136/bmjopen-2020-036860. Full text in Research Archive Show summary

  Objectives: To compare the use of benzodiazepines, z-hypnotics, gabapentinoids, opioids and centrally acting stimulants (CAS) among patients who had received opioid agonist therapy (OAT) in Norway and Sweden during the period 2015 - 2017. Design: A register-based prospective cohort study using information about dispensed drugs from the Norwegian Prescription Database and Swedish Prescribed Drug Register. Setting: Patients who were dispensed OAT opioids from pharmacies. Participants: A total of 7176 Norwegian and 3591 Swedish patients on OAT were included. Outcome measures: The number and frequency of potentially addictive drugs dispensed were calculated for the two countries. The mean daily doses of dispensed benzodiazepines and z-hypnotics were summarised by calculating benzodiazepines in diazepam equivalents and z-hypnotics in zopiclone equivalents. Results: In 2017, 46% of patients in Norway, and 15% in Sweden, were dispensed a benzodiazepine. Moreover, 14% in Norway and 26% in Sweden received z-hypnotics. Gabapentinoids were dispensed to 10% of patients in Norway and 19% of patients in Sweden. In Norway, 6% and 12% of the patients received strong and weak non-OAT opioids, respectively, whereas in Sweden 10% were dispensed strong non-OAT opioids and 5% weak non-OAT opioids . CAS were dispensed to 4% in Norway and 18% in Sweden. The mean daily doses of benzodiazepines were 16 and 17 mg diazepam equivalents in Norway and Sweden, respectively. For z-hypnotics, the mean daily dose was 8 mg zopiclone equivalents in both countries. ‘Benzodiazepines and z-hypnotics’ was the most dispensed drug combination in 2017. Similar results were found in 2015 and 2016. Conclusions: Nearly half of those patients who were dispensed an OAT opioid in Norway and Sweden were dispensed potentially addictive drugs. The differences identified between Norway and Sweden might be related to differences in eligibility guidelines and restrictions with respect to OAT.

• Vold, Jørn Henrik; Aas, Christer Frode; Skurtveit, Svetlana; Odsbu, Ingvild; Chalabianloo, Fatemeh & Halmøy, Anne [Show all 8 contributors for this article] (2020). Dispensation of attention deficit hyperactivity disorder (ADHD) medications in patients receiving opioid agonist therapy; A national prospective cohort study in Norway from 2015 to 2017. BMC Psychiatry. 20, p. 1–12. doi: 10.1186/s12888-020-02526-y. Full text in Research Archive Show summary

  Background It is estimated that up to a third of patients on opioid agonist therapy (OAT) have attention deficit hyperactivity disorder (ADHD). Treatment by ADHD medication, including a centrally acting stimulant (CAS) or atomoxetine is one of the essential approaches. This study evaluates the use of dispensed ADHD medications in the Norwegian OAT population in the period from 2015 to 2017. Types and doses of ADHD medications, co-dispensations of other potentially addictive drugs like benzodiazepines, z-hypnotics, gabapentinoids, and non-OAT opioids, as well as direct-acting antivirals (DAA) against hepatitis C infection, are investigated. Methods Information about all dispensed ADHD medication, OAT opioids, and the defined potentially addictive drugs were recorded from the Norwegian Prescription Database. Dispensation rates, the types, and the doses of dispensed ADHD medications were estimated by summarizing the number of dispensations, and the dispensed doses. Logistic regression analyses were employed to assess the associations between ADHD medication, and OAT opioid use, and dispensations of other potentially addictive drugs and DAAs against hepatitis C infection. Results A total of 9235 OAT patients were included. The proportion of patients who were dispensed ADHD medication increased from 3.5 to 4.6% throughout the study period. The three most dispensed CAS were short- and intermediate-acting methylphenidate (55%), lisdexamphetamine (24%), and dexamphetamine (17%) in 2017. Buprenorphine, rather than methadone, as OAT opioid (adjusted odds ratio: 1.6, CI: 1.2–2.1) was associated with being dispensed ADHD medication. Among patients who received CAS and OAT opioids each calendar year, the dispensed doses of methylphenidate increased from 63 mg/day in 2015 to 76 mg/day in 2017 (p = 0.01). Sixty percent of patients receiving ADHD medications were also dispensed other addictive drugs concomitantly in 2017. Similar results were found in 2015 and 2016. Conclusion Co-prescription of ADHD medications was low among patients on OAT in Norway, considering a high prevalence of ADHD in this patient group. On the other hand, concurrent dispensations of multiple addictive drugs were common in this population. Understanding the underlying reasons for such prescribing is essential, and research on how to optimize ADHD medication of patients with ADHD receiving OAT is needed.

• Aas, Christer Frode; Vold, Jørn Henrik; Skurtveit, Svetlana; Odsbu, Ingvild; Chalabianloo, Fatemeh & Økland, Jan-Magnus [Show all 10 contributors for this article] (2020). On the path towards universal coverage of hepatitis C treatment among people receiving opioid agonist therapy (OAT) in Norway: A prospective cohort study from 2013 to 2017. BMJ Open. 10(8), p. 1–9. doi: 10.1136/bmjopen-2019-036355. Full text in Research Archive Show summary

  Objectives We aimed to calculate cumulative hepatitis C virus (HCV) treatment coverage among individuals enrolled in opioid agonist therapy (OAT) in Norway between 2013 and 2017 and to document the treatment transition to direct-acting antiviral (DAA) agents. Moreover, we aimed to describe adherence to DAAs in the same cohort. Design Prospective cohort, registry data. Setting Specialist healthcare service (secondary) Participants and outcomes This observational study was based on data from The Norwegian Prescription Database. We studied dispensed OAT and HCV treatment annually to calculate the cumulative frequency, and employed secondary sources to calculate prevalence, incidence and HCV treatment coverage from 2013 to 2017, among the OAT population. Factors associated with adherence to DAAs were identified a priori and subject to logistic regression. Results 10 371 individuals were identified with dispensed OAT, 1475 individuals of these were identified with dispensed HCV treatment. Annual HCV treatment coverage increased from 3.5% (95% CI: 3.2 to 4.4) in 2013 to 17% (95% CI: 17 to 20) in 2017, giving a cumulative HCV coverage among OAT patients in Norway of 38.5%. A complete shift to interferon-free treatment regimens occurred, where DAAs accounting for 32% of HCV treatments in 2013 and 99% in 2017. About two-thirds of OAT patients were considered adherent to their DAA regimens across all genotypes. High level of OAT continuity was associated with improved adherence to DAAs (adjusted OR 1.4, 95% CI: 1 to 2, p=0.035). Conclusions A large increase in HCV treatment coverage attributed by a complete shift to interferon-free regimens among the Norwegian OAT population has been demonstrated. However, treatment coverage is inadmissibly too low and a further substantial scale-up in HCV treatment is required to reach the universal targets of controlling and eliminating the HCV endemic.

• Cesta, Carolyn E.; Cohen, Jacqueline Mallory; Pazzagli, Laura; Bateman, Brian T.; Bröms, Gabriella & Einarsdottir, Kristjana [Show all 20 contributors for this article] (2019). Antidiabetic medication use during pregnancy: an international utilization study. BMJ Open Diabetes Research & Care. 7:E000759, p. 1–12. doi: 10.1136/bmjdrc-2019-000759. Full text in Research Archive
• Odsbu, Ingvild; Skurtveit, Svetlana; Selmer, Randi; Roth, Christine; Hernandez-Diaz, Sonia & Handal, Marte (2015). Prenatal exposure to anxiolytics and hypnotics and language competence at 3 years of age. European Journal of Clinical Pharmacology. ISSN 0031-6970. 71(3), p. 283–291. doi: 10.1007/s00228-014-1797-4. Full text in Research Archive
• Skurtveit, Svetlana; Selmer, Randi; Odsbu, Ingvild & Handal, Marte (2014). Self-reported data on medicine use in the Norwegian mother and child cohort study compared to data from the Norwegian prescription database. Norsk Epidemiologi. ISSN 0803-2491. 24(1-2), p. 209–216. doi: 10.5324/nje.v24i1-2.1824. Full text in Research Archive

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• Skurtveit, Svetlana Ondrasova & Odsbu, Ingvild (2026). Rekvirenttilbakemeldinger (tiltak 10.2) og kunnskap (tiltak 10.5). Full text in Research Archive
• Odsbu, Ingvild (2026). Legemiddelavhengighet og overdoser. Full text in Research Archive
• Odsbu, Ingvild (2025). Oversikt over opioidbruk i Norge. Full text in Research Archive
• Rolová, Gabriela; Engeland, Anders; Pedersen, Line; Odsbu, Ingvild; Hamina, Aleksi & Skurtveit, Svetlana Ondrasova (2025). Reply to the Chen and Chen. Pain. ISSN 0304-3959. 166(10), p. e493–e494. doi: 10.1097/j.pain.0000000000003741. Full text in Research Archive
• Finnes, Trine Elisabeth; Ruiz, Paz Lopez-Doriga; Karlstad, Øystein; Odsbu, Ingvild; Meyer, Haakon Eduard & Holvik, Kristin (2025). Risk of hip fracture in patients with type 2 diabetes treated with Glucagon- Like Peptide-1 Receptor Agonists (GLP-1ras) versus Dipeptidyl Peptidase 4 Inhibitors (DPP4i) in Norway: A registry-based comparative study. Norsk Epidemiologi, Supplement. ISSN 0803-4206. 33(Suppl.1), p. 14–14. doi: https:/www.ntnu.no/ojs/index.php/norepid/index. Full text in Research Archive Show summary

  Introduction: GLP-1RAs, which are used to regulate blood glucose in type 2 diabetes, also induce weight loss. Their use has surged dramatically in recent years. Rapid weight loss is associated with fracture risk. Furthermore, type 2 diabetes is an independent risk factor for hip fracture, with proposed mechanisms including inflammation, poor physical functioning and pharmacological treatments. Aims: To compare the risk of hip fracture in patients with type 2 diabetes after starting treatment with GLP-1RAs and DPP4i, respectively. Methods: We used data from the Norwegian Prescribed Drug Registry, the Norwegian Epidemiologic Osteoporosis Studies (NOREPOS) hip fracture database and Statistics Norway. We included incident users of GLP-1RAs or DPP4i aged 50+ years who had previously used metformin, had a diagnosis of type 2 diabetes as reimbursement code for their first GLP-1RA or DPP4i fill, and filled at least two prescriptions. We excluded those with a history of treatments implying advanced chronic kidney disease, any previous fill of thiazolidinediones (associated with osteoporosis), or fill of hypoglycemiainducing antidiabetics (affecting fall risk) within three months before the first fill of GLP-1RA or DPP4i. We performed Cox proportional hazards regression with hip fracture as outcome and age as timescale, adjusted for calendar year (categorical) and comorbidity expressed by the Rx-Risk Comorbidity Index for the calendar year prior to initiation (splines). In the analysis reflecting intention-to-treat, all were followed from their second filling of the initiator drug to a hip fracture, emigration, death, or 31.12.2023, whichever occurred first, disregarding cumulative dose, change of medication, discontinuation, and other drug use. Results: The study population included 23 605 GLP-1RA initiators (45% women) and 50 068 DPP4i initiators (38% women) during 2008-2023, with mean (SD) age 61.6 (8.8) years in GLP-1RA initiators and 65.7 (10.5) years in DPP4i initiators. During 346,079 person-years, 1,657 hip fractures occurred. Hazard ratios (95% confidence intervals) for hip fracture in GLP-1RA vs. DPP4i initiators were 0.70 (0.53, 0.92) in women and 0.98 (0.73, 1.31) in men. Conclusions: In an intention-to-treat design, we found a statistically significant lower risk of hip fracture in women who started GLP-1RAs compared with DPP4i, but no difference in men.

• Skurtveit, Svetlana Ondrasova & Odsbu, Ingvild (2025). Handlingsplanen mot overdoser, del B. Full text in Research Archive
• Odsbu, Ingvild (2025). Opioidepidemi i Norge? Full text in Research Archive
• Clavenna, Antonio & Odsbu, Ingvild (2024). Drug utilization in the paediatric population. In Elseviers, Monique; Wettermark, Björn; Mueller, Tanja; Benko, Ria; Bennie, Marion; Gvozdanovic, Katarina; Hoffmann, Mikael; Iaru, Irina; Ivanovska, Verica; Macbride-Stewart, Sean; Poluzzi, Elisabetta; Pont, Lisa; Blix, Hege Salvesen; Sanfelix-Gimeno, Gabriel; Selke, Gisbert; Taxis, Katja; Petrovic, Ana Tomas; Treciokiene, Indre & Vogler, Sabine (Ed.), Drug Utilization Research: Methods and Applications, 2nd Edition. Wiley-Blackwell. ISSN 9781119911661. p. 314–320. Full text in Research Archive
• Nestvold, Håkon Høydal; Skurtveit, Svetlana Ondrasova & Odsbu, Ingvild (2024). Sosioøkonomiske vansker øker sjansen for utvikle langvarig opioidbruk uavhengig av smertetilstander. Glimt. ISSN 1890-8489. 1-2024, p. 14–15. Full text in Research Archive
• Rolová, Gabriela; Engeland, Anders; Odsbu, Ingvild; Hjellvik, Vidar & Skurtveit, Svetlana Ondrasova (2024). Mortality among patients with long-term prescription opioid use in Norway. Full text in Research Archive
• Odsbu, Ingvild (2024). Kan bli milliardbelønning for fentanyl-vaksine. [Journal]. VG. Full text in Research Archive
• Odsbu, Ingvild & Skurtveit, Svetlana Ondrasova (2024). Opioidepidemi i Norge? Full text in Research Archive
• Hartz, Ingeborg; Cohen, Jacqueline Mallory; Skurtveit, Svetlana Ondrasova; Andersen, Per Normann; Handal, Marte & Odsbu, Ingvild (2024). Psychotropic Drug Use Among 0–17 Year Old Norwegians During 2014–2021: A Nationwide Register Study. Full text in Research Archive
• Hartz, Ingeborg; Cohen, Jacqueline Mallory; Skurtveit, Svetlana Ondrasova; Andersen, Per Normann; Handal, Marte & Odsbu, Ingvild (2024). Psychotropic Drug Use Among 0–17 Year Old Norwegians During 2014–2021: A Nationwide Register Study. Pharmacoepidemiology and Drug Safety. ISSN 1053-8569. 33. doi: 10.1002/pds.5891. Full text in Research Archive
• Odsbu, Ingvild (2024). Socioeconomic risk factors for long-term prescription opioid use: A national registry-linkage study. Full text in Research Archive
• vambheim, Sara Magelssen; Hjellvik, Vidar; Odsbu, Ingvild; Skurtveit, Svetlana Ondrasova; Ekholdt, Christopher & Granan, Lars-Petter Ness [Show all 8 contributors for this article] (2023). Postoperative Opioid Use in Norway - Patterns of Prolonged Use. Full text in Research Archive
• Skurtveit, Svetlana Ondrasova; Hamina, Aleksi & Odsbu, Ingvild (2023). Overdose risk-increasing medication is more often dispensed to individuals dying of overdoses related to pharmaceutical available opioids compared to individuals dying of overdoses related to other substances: a population-based register study. Full text in Research Archive
• Odsbu, Ingvild; Hjellvik, Vidar; Hamina, Aleksi & Skurtveit, Svetlana Ondrasova (2023). Prevalence of pain-related and mental health diagnoses among persistent opioid users: a population-based registry-linkage study. Full text in Research Archive
• Odsbu, Ingvild (2023). Opioider ved langvarige smerter. Full text in Research Archive
• Odsbu, Ingvild (2023). Nyheter: En av ti tar ut sterke smertestillende. [Radio]. P4. Full text in Research Archive
• Nestvold, Håkon Høydal; Skurtveit, Svetlana Ondrasova; Hamina, Aleksi; Hjellvik, Vidar & Odsbu, Ingvild (2023). Socioeconomic risk factors for long-term opioid use: a national registry-linkage study. Full text in Research Archive
• Odsbu, Ingvild (2023). Kunnskapsgrunnlag. Full text in Research Archive
• Odsbu, Ingvild (2023). Forskrivning de siste 20 årene. Full text in Research Archive
• Skurtveit, Svetlana Ondrasova; Nestvold, Håkon Høydal & Odsbu, Ingvild (2023). Flere bruker opioider over lang tid. Glimt. ISSN 1890-8489. p. 10–11. Full text in Research Archive
• Odsbu, Ingvild (2022). Vi er bekymret. [Internet]. Sol.no. Full text in Research Archive
• Odsbu, Ingvild (2022). Stadig flere bruker sterke smertestillende over lang tid – FHI er bekymret. [Journal]. Vårt Land. Full text in Research Archive
• Odsbu, Ingvild (2022). FHI om opioid-tall: - Vi er bekymret. [Journal]. Sol.no. Full text in Research Archive
• Odsbu, Ingvild (2022). Smertestillende piller og overdosedød. Full text in Research Archive
• Odsbu, Ingvild (2022). Stadig flere bruker sterke smertestillende over lang tid – FHI er uroleg. [Journal]. Folkebladet. Full text in Research Archive
• Odsbu, Ingvild (2022). Stadig fleire bruker sterke smertestillande over lang tid – FHI er uroleg. [Journal]. Fjordabladet. Full text in Research Archive
• Odsbu, Ingvild (2022). Kommentar: I. Odsbu og medarbeidere svarer. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 142(3). doi: 10.4045/tidsskr.21.0659. Full text in Research Archive
• Odsbu, Ingvild (2022). Vedvarende opioidbruk og samtidig bruk av andre vanedannende legemidler. Full text in Research Archive
• Gjerde, Line Cecilie; Handal, Marte; Nesvåg, Ragnar; Clausen, Thomas; Lid, Torgeir Gilje & Hamina, Aleksi [Show all 8 contributors for this article] (2022). A nationwide registry-linkage study of mental disorders in chronic pain patients: Characteristics of users of opioid versus non-opioid analgesics. Full text in Research Archive
• Hamina, Aleksi; Odsbu, Ingvild; Hjellvik, Vidar; Gjersing, Linn; Lid, Torgeir Gilje & Clausen, Thomas [Show all 7 contributors for this article] (2022). Fatal overdoses in a cohort of chronic pain patients. Full text in Research Archive
• Odsbu, Ingvild; Handal, Marte; Borchgrevink, Petter Chr.; Clausen, Thomas & Skurtveit, Svetlana Ondrasova (2022). Endringer i opioidbruken i Norge må tas på dypeste alvor. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. doi: 10.4045/tidsskr.21.0909. Full text in Research Archive
• Odsbu, Ingvild (2022). Trends in use of prescribed opioids in Norway – should we be concerned? Full text in Research Archive
• Skurtveit, Svetlana Ondrasova & Odsbu, Ingvild (2022). Resultater fra tildelingsbrev og utvalgte resultater fra pågående forskningsprosjekt (POINT). Full text in Research Archive
• Skurtveit, Svetlana Ondrasova & Odsbu, Ingvild (2022). Resultater fra oppdrag i tildelingsbrevet for 2020 – fokus på blåreseptordningen. Full text in Research Archive
• Hamina, Aleksi; Odsbu, Ingvild; Clausen, Thomas & Skurtveit, Svetlana Ondrasova (2022). Intentional overdoses and associated mental health challenges, an overlooked sub-population of overdoses. Full text in Research Archive
• Odsbu, Ingvild; Handal, Marte; Hjellvik, Vidar & Skurtveit, Svetlana Ondrasova (2021). Trends in long-term use of prescribed opioids in Norway 2010-2019. Pharmacoepidemiology and Drug Safety. ISSN 1053-8569. 30, p. 53–53. doi: 10.1002/pds.5305. Full text in Research Archive Show summary

  Background Since 2008, patients with chronic, non-malignant pain conditions can get reimbursement for analgesic opioids. There is limited evidence of analgesic effect of opioids when used over a long time period while the risk of adverse effects is increasing. Thus, closely monitoring of opioid consumption at the population level to detect signs of escalation is needed. Objectives To investigate whether there has been a change in the number of long-term users of prescribed opioids over time and according to reimbursement scheme (reimbursed opioids for palliative care, reimbursed opioids for chronic, non-malignant pain, or non-reimbursable opioids). Methods Data were retrieved from the Norwegian Prescription Database. The study population consisted of all individuals filling at least one prescription of an opioid (ATC N02A) during 2010-2019. Long-term use was defined as being dispensed more than 180 defined daily doses or more than 4500 mg oral morphine equivalents of opioids a given year and filling prescriptions in at least 3 quarters of the year. Individuals were divided into mutually exclusive groups according to reimbursement scheme in a hierarchical manner; reimbursed opioids for palliative care > reimbursed opioids for chronic, non-malignant pain > non-reimbursable opioids. The proportion of long-term opioid users according to reimbursement scheme was calculated. Results The number of long-term opioid users increased from 49,993 in 2010 to 59,996 in 2019. The increase over time was almost solely attributed to an increase among chronic, non-malignant pain patients. The number of long-term users receiving non-reimbursable opioids and opioids for palliative care remained stable over time. In 2019, the majority of the 59,996 long-term users received non-reimbursable opioids only (n=38,006), followed by long-term users receiving opioids for chronic, non-malignant pain (n=14,812), and long-term users receiving palliative care (n=7,178). Conclusions The number of long-term opioid users have increased by 20% (10,000 individuals) over an 11 years period in Norway due to an increase in number of long-term users receiving reimbursed opioids to treat chronic, non-malignant pain. More studies are needed to understand whether the introduction of the reimbursement scheme for chronic pain patients has been a contributing factor to the observed increase in number of long-term opioid users and why the majority of the long-term opioid users do not receive opioids according to the reimbursement scheme for chronic, non-malignant pain.

• Odsbu, Ingvild; Handal, Marte; Hjellvik, Vidar & Skurtveit, Svetlana Ondrasova (2021). Trends in long-term use of prescribed opioids in Norway 2010-2019. Full text in Research Archive
• Odsbu, Ingvild; Handal, Marte; Hjellvik, Vidar & Skurtveit, Svetlana Ondrasova (2021). Trends in long-term use of prescribed opioids in Norway 2010-2019. Full text in Research Archive
• Steingrímsdóttir, Ólöf Anna; Nielsen, Christopher Sivert; Odsbu, Ingvild; Skurtveit, Svetlana Ondrasova & Handal, Marte (2018). Langvarig smerte i Norge. In Grøholt, Else Karin; Bøhler, Linn & Hånes, Hanna (Ed.), Folkehelserapporten - Helsetilstanden i Norge. Folkehelseinstituttet. Full text in Research Archive
• Hansen, Thomas; Reneflot, Anne; Kirkøen, Benedicte; Strand, Bjørn Heine; Vedaa, Øystein & Bye, Elin Kristin [Show all 10 contributors for this article] (2025). En kartlegging av psykisk helse og livskvalitet blant eldre i Norge. Folkehelseinstituttet. Full text in Research Archive Show summary

• Berg, Christian Lie; Blix, Hege Salvesen; Fenne, Olaug Sveinsgjerd; Husabø, Kari Jansdotter; Litleskare, Irene & Odsbu, Ingvild (2015). Reseptregisteret 2010-2014. Tema: Antibiotika / The Norwegian prescription database 2010-2014. Topic: Antibiotics. Nasjonalt folkehelseinstitutt / The Norwegian Institute of Public Health. ISSN 9788280826657. Full text in Research Archive
• Berg, Christian Lie; Karlstad, Øystein; Mahic, Milada & Odsbu, Ingvild (2014). Reseptregisteret 2009-2013. The Norwegian prescription database 2009-2013. Folkehelseinstituttet. ISSN 9788280826190. Full text in Research Archive

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