Birgitte Lawaetz Myhrvold

• Julsvoll, Elisabeth Heggem; Myhrvold, Birgitte Lawaetz; Waagan, Knut; Vøllestad, Nina Køpke & Robinson, Hilde Stendal (2024). Identifying phenotypes in persons with temporomandibular disorders using latent class analyses. Journal of Oral Rehabilitation. ISSN 0305-182X. doi: 10.1111/joor.13837. Full text in Research Archive Show summary

  Background The heterogeneity of persons with temporomandibular disorders (TMD) and the lack of effective treatments have called for a biopsychosocial model and the development of a more personalised treatment approach. Emphasis on phenotypes might be a beneficial approach. Objective Identifying phenotypes among persons with TMD using potential prognostic factors, including personal characteristics and responses to clinical tests. Additionally, examining the distribution of TMD diagnoses within the identified phenotypes. Methods A cross-sectional study including 208 persons (85% females) seeking physiotherapy for problems in the temporomandibular area. All participants were examined clinically and answered questionnaires electronically. The phenotypes were identified using latent class analysis based on seven potential prognostic factors selected within pain, function and psychological domains. Table analysis was used to explore the distribution of TMD diagnoses within the identified phenotypes. Results Most participants fit into one of three identified phenotypes. Phenotype 1 (32%) was characterised by functional disability, low psychosocial scores and low risk for developing chronicity and future work disability; Phenotype 2 (29%) by parafunctional habits, low psychosocial score and seeking treatment to reduce pain; and Phenotype 3 (39%) by high levels of mental distress, fear avoidance and a large risk of future work disability. Intra-articular disorders dominated Phenotype 1, myalgia and TMD-related headache Phenotype 2, while Phenotype 3 included all the different TMD diagnoses. Conclusion The knowledge about the three identified phenotypes might be useful for clinicians treating persons with TMD and for the development of preventive strategies and more personalised treatment.

• Myhrvold, Birgitte Lawaetz; Vikhaug, Tora Bjørkmann; DuRose, Alister; Gausel, Anne Marie; Eklund, Andreas & Axén, Iben (2023). Evidence-based maintenance care among chiropractors in Norway: a cross-sectional survey in the Nordic maintenance care program. Chiropractic & Manual Therapies. 31(1). doi: 10.1186/s12998-023-00502-3. Full text in Research Archive Show summary

  Background Chiropractors use a treatment strategy called maintenance care with the intent of secondary and tertiary prevention. The Nordic Maintenance Care Program provides evidence of when and for whom maintenance care should be offered. Dissemination has occurred through articles, workshops, social media, conference in Europe and internationally. However, little is known about chiropractors’ awareness and use of this evidence. This study explores chiropractors’ attitudes, skills, and use of evidence on maintenance care, as well as study their association with general evidence-based practice and demographic characteristics. Moreover, barriers and facilitators of evidence access are also examined. Methods Questions pertaining our research aim were included in the anonymous and digital Evidence-Based practice Attitude and utilization SurvEy, which was distributed to all members (n = 770) of the Norwegian chiropractic association in the fall of 2021. Results The response rate was 41% (n = 312). Regarding attitudes towards evidence-based maintenance care, 26% agreed they needed tools to recommend this care to patients. Approximately half (57%) believed they had skills to identify suitable patients, and 45% had used published information in the past month. Strong alignment was observed between Norwegian chiropractors’ attitudes, skills, and utilization of evidence-based maintenance care and general evidence-based practice. Maintenance care skills were significantly associated with age (those between 40 and 59 years being less likely to report having high skills), clinical setting (those working with conventional health care providers being less likely to report having high skills) and country of education (those educated in the US and Australia being more likely to report having high skills). Moreover, maintenance care use was significantly associated with country of education (those educated in Australia were less likely to have used published information regarding patient selection for maintenance care). Access to resources was a barrier, whereas knowledge of patient suitability facilitated evidence-based maintenance care. Conclusions Norwegian chiropractors had neutral attitudes towards maintenance care, but generally reported moderate skills. Most had not used evidence about maintenance care in the previous month. Access to useful resources about the evidence regarding maintenance care was a barrier, and knowledge of who responds to maintenance care was a facilitator.

• Myhrvold, Birgitte Lawaetz; Vøllestad, Nina Køpke; Irgens, Pernille Marie Stähr; Robinson, Hilde Stendal & Axén, Iben (2023). Clinical indicators for recommending continued care to patients with neck pain in chiropractic practice: a cohort study. Chiropractic & Manual Therapies. 31(1). doi: 10.1186/s12998-023-00507-y. Full text in Research Archive Show summary

  Background Chiropractors’ clinical indicators for recommending preventive continued care to patients with low back pain include previous pain episodes, a history of long pain duration and improvement after initial treatment. Our objectives were, in a cohort of patients with neck pain, to examine whether these clinical indicators were associated with being recommended continued care beyond 4 weeks, and if so whether this recommendation was dependent of chiropractor characteristics, as well as if the number of clinical indicators influenced this recommendation. Methods In this multi-center observational study, 172 patients seeking care for a new episode of neck pain in chiropractic practice in Norway were included between September 2015 and May 2016. The chiropractors treated their patients as per usual, and for this study, baseline data and 4-week follow-up data were used. Patient data included the clinical indicators (1) previous episodes of neck pain, (2) a history of long duration neck pain and (3) improvement four weeks after initial treatment. The recruiting chiropractors were asked at 4-week follow-up if each patient was recommended continued care, defined as care planned beyond the first 4 weeks. Univariate and multivariable logistic regression models investigated the association between clinical indicators and the continued care recommendation, as well as the influence of chiropractor characteristics on this recommendation. Cross tabulations investigated the relationship between the number of indicators present and recommendation of continued care. Results Long duration of neck pain was the strongest clinical indicator for being recommended continued care 4 weeks after the initial treatment. Chiropractor characteristics were not associated with this recommendation. In patients with all three clinical indicators present, 39% were recommended continued care. When two and one indicators were present, the percentages of those recommended continued care were 25% and 10%, respectively. Conclusion Chiropractors recommended continued care for patients experiencing neck pain based on their history of long pain duration, and this was not influenced by characteristics of the chiropractor. This differs from previous studies of indicators for maintenance care in patients with low back pain.

• Myhrvold, Birgitte Lawaetz; Axén, Iben; Leach, Matthew J; Sundberg, Tobias & Gausel, Anne Marie (2023). Investigating attitudes, skills, and use of evidence-based practice among Norwegian chiropractors; a national cross-sectional study. BMC Health Services Research. 23(1). doi: 10.1186/s12913-023-09354-2. Full text in Research Archive Show summary

  Background Evidence-based practice (EBP) is essential in improving the quality of healthcare and of importance for all health care personnel. No study in Norway has investigated attitudes, skills and use related to EBP among chiropractors. The aim of this study was to describe Norwegian chiropractors’ attitudes, skills, and use of EBP, as well as the barriers and facilitators to their use of EBP. Methods A national cross-sectional survey, the online version of the Evidence Based practice Attitudes & Utilisation SurvEy (EBASE), was sent by email to 770 Norwegian practicing chiropractors, all members of the Norwegian Chiropractic Association. Three EBASE sub-scores were generated (Attitudes, Skills and Use), and the demographic characteristics of the sample were reported. Linear regression analyses were conducted to examine the association between responses of the three sub-scores and demographic characteristics. Information on main barriers and facilitators of EBP was collected and described. Results A total of 312 (41%) chiropractors responded to the survey, and 95% agreed that EBP is necessary for chiropractic practice. While overall use of EBP activities was low participants were interested in learning and improving their skills to incorporate EBP into practice. Chiropractors’ attitudes, skills, and use of EBP were positively associated with being female and having spent more than one hour per week on research, but negatively associated with having practiced more than 10 years. Main barriers of EBP were lack of skills to critically evaluate, interpret, and apply research findings to practice. Main facilitators of EBP included access to the internet and free online databases in the workplace. Conclusion Although chiropractors in Norway reported positive attitudes and moderate skills in EBP, their use of EBP activities was limited. The main barriers and facilitators to EBP were primarily related to perceived skills deficits, whilst enablers of EBP were mostly related to infrastructure requirements.

• Irgens, Pernille Marie Stähr; Myhrvold, Birgitte Lawaetz; Kongsted, Alice; Natvig, Bård; Vøllestad, Nina Køpke & Robinson, Hilde Stendal (2022). Exploring visual pain trajectories in neck pain patients, using clinical course, SMS-based patterns, and patient characteristics: a cohort study. Chiropractic & Manual Therapies. 30(1), p. 37–37. doi: 10.1186/s12998-022-00443-3. Full text in Research Archive Show summary

  Background The dynamic nature of neck pain has so far been identified through longitudinal studies with frequent measures, a method which is time-consuming and impractical. Pictures illustrating different courses of pain may be an alternative solution, usable in both clinical work and research, but it is unknown how well they capture the clinical course. The aim of this study was to explore and describe self-reported visual trajectories in terms of details of patients’ prospectively reported clinical course, their SMS-based pattern classification of neck pain, and patient’s characteristics. Methods Prospective cohort study including 888 neck pain patients from chiropractic practice, responding to weekly SMS-questions about pain intensity for 1 year from 2015 to 2017. Patients were classified into one of three clinical course patterns using definitions based on previously published descriptors. At 1-year follow-up, patients selected a visual trajectory that best represented their retrospective 1-year course of pain: single episode, episodic, mild ongoing, fluctuating and severe ongoing. Results The visual trajectories generally resembled the 1-year clinical course characteristics on group level, but there were large individual variations. Patients selecting Episodic and Mild ongoing visual trajectories were similar on most parameters. The visual trajectories generally resembled more the clinical course of the last quarter. Discussion The visual trajectories reflected the descriptors of the clinical course of pain captured by weekly SMS measures on a group level and formed groups of patients that differed on symptoms and characteristics. However, there were large variations in symptoms and characteristics within, as well as overlap between, each visual trajectory. In particular, patients with mild pain seemed predisposed to recall bias. Although the visual trajectories and SMS-based classifications appear related, visual trajectories likely capture more elements of the pain experience than just the course of pain. Therefore, they cannot be seen as a proxy for SMS-tracking of pain over 1 year.

• Myhrvold, Birgitte Lawaetz; Kongsted, Alice; Irgens, Pernille Marie Stähr; Robinson, Hilde Stendal & Vøllestad, Nina Køpke (2022). The association between different outcome measures and prognostic factors in patients with neck pain: a cohort study. BMC Musculoskeletal Disorders. 23(1). doi: 10.1186/s12891-022-05558-5. Full text in Research Archive Show summary

  Background Health domains like pain, disability, and health-related quality of life are commonly used outcomes for musculoskeletal disorders. Most prognostic studies include only one outcome, and it is unknown if prognostic factors and models may be generic across different outcomes. The objectives of this study were to examine the correlation among commonly used outcomes for neck pain (pain intensity, disability, and health-related quality of life) and to explore how the predictive performance of a prognostic model differs across commonly used outcomes. Methods We conducted an observational prospective cohort study with data from patients with neck pain aged 18–84 years consulting Norwegian chiropractors. We used three different outcomes: pain intensity (Numeric Pain Rating Scale), the Neck Disability Index (NDI), and health-related quality of Life (EQ-5D). We assessed associations between change in outcome scores at 12-weeks follow-up with Pearson’s correlation coefficient. We used multivariable linear regression models to explore differences in explained variance and relationship between predictors and outcomes. Results The study sample included 1313 patients and 941 (72%) completed follow-up at 12 weeks. The strongest correlation was between NDI and EQ-5D (r = 0.57) while the weakest correlation was between EQ-5D and pain intensity (r = 0.39). The correlation between NDI and pain intensity was moderate (r = 0.53) In the final regression models, the explained variance ranged from adjusted R2 of 0.26 to 0.60, highest with NDI and lowest with pain intensity as outcome. The predictive contributions of the included predictors were similar across outcomes. Among the investigated predictors, pain patterns and the baseline measure of the corresponding outcome measure contributed the most to explained variance across all outcomes. Conclusions The highest correlation was found between NDI and EQ-5D and the lowest with pain intensity. The same prognostic model showed highest predictive performance with NDI as outcome and poorest with pain intensity as outcome. These results suggest that we need more knowledge on the reasons for the differences in predictive performance variation across outcomes.

• Irgens, Pernille Marie; Myhrvold, Birgitte Lawaetz; Kongsted, Alice; Waagan, Knut; Engebretsen, Kaia Beck & Vøllestad, Nina Køpke [Show all 7 contributors for this article] (2021). The clinical course of neck pain: Are trajectory patterns stable over a 1-year period? European Journal of Pain. ISSN 1090-3801. p. 1–12. doi: 10.1002/ejp.1879. Full text in Research Archive Show summary

  Background Recent studies with data-driven approaches have established common pain trajectories. It is uncertain whether these trajectory patterns are consistent over time, and if a shorter measurement period will provide accurate trajectories. Methods We included 1,124 patients with non-specific neck pain in chiropractic practice. We classified patients into pre-defined trajectory patterns in each of four quarters of the follow-up year (persistent, episodic, and recovery) based on measures of pain intensity and frequency from weekly SMS. We explored the shifts between patterns and compared patients with stable and shifting patterns on baseline characteristics and clinical findings. Results 785 (70%) patients were in the same pattern in 1st and 4th quarters. Patients with episodic pattern in the 1st quarter shifted to other patterns more frequently than patients in the other patterns. A stable persistent pattern was associated with reduced function and higher scores on psychosocial factors. There was a decreased frequency of patients classified as persistent pattern (75% to 63%) and an increase of patients in recovery pattern (4% to 15%) throughout the four quarters. The frequency of patients classified as episodic remained relatively stable (21% to 24%). Conclusions We found an overall stability of the persistent pattern, and that episodic patterns have more potential for shifts. Shifts mostly occurred between patterns closest in pain variation. The deviation in pattern distribution compared with previous studies suggests that the duration of measurement periods has an impact on the results of the classification. Significance Having persistent pain and having very minor pain is relatively stable over one year, while episodic pain has more potential for shifts. The duration of measurement periods appears to have an impact on the results of the classification. The given criteria resulted in a reduced frequency of episodic pattern due to shorter measurement periods. Our findings contribute to improved understanding and predicting NP using a combination of patient characteristics and trajectory patterns.

• Irgens, Pernille Marie; Kongsted, Alice; Myhrvold, Birgitte Lawaetz; Waagan, Knut; Engebretsen, Kaia Beck & Natvig, Bård [Show all 8 contributors for this article] (2020). Neck pain patterns and subgrouping based on weekly SMS-derived trajectories. BMC Musculoskeletal Disorders. 21, p. 1–14. doi: 10.1186/s12891-020-03660-0. Full text in Research Archive Show summary

  Background Neck and low back pain represent dynamic conditions that change over time, often with an initial improvement after the onset of a new episode, followed by flare-ups or variations in intensity. Pain trajectories were previously defined based on longitudinal studies of temporal patterns and pain intensity of individuals with low back pain. In this study, we aimed to 1) investigate if the defined patterns and subgroups for low back pain were applicable to neck pain patients in chiropractic practice, 2) explore the robustness of the defined patterns, and 3) investigate if patients within the various patterns differ concerning characteristics and clinical findings. Methods Prospective cohort study including 1208 neck pain patients from chiropractic practice. Patients responded to weekly SMS-questions about pain intensity and frequency over 43 weeks. We categorized individual responses into four main patterns based on number of days with pain and variations in pain intensity, and subdivided each into four subgroups based on pain intensity, resulting in 16 trajectory subgroups. We compared baseline characteristics and clinical findings between patterns and between Persistent fluctuating and Episodic subgroups. Results All but two patients could be classified into one of the 16 subgroups, with 94% in the Persistent fluctuating or Episodic patterns. In the largest subgroup, “Mild Persistent fluctuating” (25%), mean (SD) pain intensity was 3.4 (0.6) and mean days with pain 130. Patients grouped as “Moderate Episodic” (24%) reported a mean pain intensity of 2.7 (0.6) and 39 days with pain. Eight of the 16 subgroups each contained less than 1% of the cohort. Patients in the Persistent fluctuating pattern scored higher than the other patterns in terms of reduced function and psychosocial factors. Conclusions The same subgroups seem to fit neck and low back pain patients, with pain that typically persists and varies in intensity or is episodic. Patients in a Persistent fluctuating pattern are more bothered by their pain than those in other patterns. The low back pain definitions can be used on patients with neck pain, but with the majority of patients classified into 8 subgroups, there seems to be a redundancy in the original model.

• Myhrvold, Birgitte Lawaetz; Irgens, Pernille Marie; Robinson, Hilde Stendal; Engebretsen, Kaia Beck; Natvig, Bård & Kongsted, Alice [Show all 7 contributors for this article] (2020). Visual trajectory pattern as prognostic factors for neck pain. European Journal of Pain. ISSN 1090-3801. 24(9), p. 1752–1764. doi: 10.1002/ejp.1622. Full text in Research Archive Show summary

  Background A novel approach capturing both temporal variation and pain intensity of neck pain is by visual trajectory patterns. Recently, both previous and expected visual trajectory patterns were identified as stronger predictors of outcome than traditional measures of pain history and psychological distress. Our aim was to examine patient characteristics within the various previous and expected patterns, relationship between the two patterns and predictive value of a variable combining the previous and expected patterns. Methods Patients with neck pain (n = 932) consulting chiropractors were included. Baseline measures included pain intensity, disability, psychological variables and symptom history and expectations. Participants reported global perceived effect after 12 weeks. Analyses included descriptive statistics and logistic regression. Results Pain intensity, disability, psychological and worse outcome expectations increased from a single pain episode to severe ongoing pain of previous and expected patterns. Having a severe pain history was associated with poor prognosis, particularly if combined with negative expectations. The variable combining previous and expected patterns had a discriminative ability similar to that of other predictors AUC = 0.64 (95% CI = 0.60–0–67) versus AUC = 0.66 (95% CI = 0.62–0.70). The model with highest discriminative ability was achieved when adding the combined patterns to other predictors AUC = 0.70 (95% CI = 0.66–0.73). Conclusion The study indicates that pain expectations are formed by pain history. The patients’ expectations were similar to or more optimistic compared with their pain history. The prognostic ability of the model including a simplified combination of previous and expected patterns, together with a few other predictors, suggests that the trajectory patterns might have potential for clinical use. Significance The dynamic nature of neck pain can be captured by visual illustrations of trajectory patterns. We report, that trajectory patterns of pain history and future expectations to some extent are related. The patterns also reflect a difference in severity assessed by higher degree of symptoms and distress. Moreover, the visual trajectory patterns predict outcome at 12‐weeks. Since the patterns are easily applicable, they might have potential as a clinical tool.

• Myhrvold, Birgitte Lawaetz; Kongsted, Alice; Irgens, Pernille Marie; Robinson, Hilde Stendal; Thoresen, Magne & Vøllestad, Nina Køpke (2019). Broad External Validation and Update of a Prediction Model for Persistent Neck Pain After 12 Weeks. Spine. ISSN 0362-2436. 44(22), p. E1298–E1310. doi: 10.1097/BRS.0000000000003144. Full text in Research Archive Show summary

  Study Design. A prospective observational study. Objective. To externally validate the prediction model developed by Schellingerhout and colleagues predicting global perceived effect at 12 weeks in patients with neck pain and to update and internally validate the updated model. Summary of Background Data. Only one prediction model for neck pain has undergone some external validation with good promise. However, the model needs testing in other populations before implementation in clinical practice. Methods. Patients with neck pain (n = 773) consulting Norwegian chiropractors were followed for 12 weeks. Parameters from the original prediction model were applied to this sample for external validation. Subsequently, two random samples were drawn from the full study sample. One sample (n = 436) was used to update the model; by recalibration, removing noninformative covariates, and adding new possible predictors. The updated model was tested in the other sample (n = 303) using stepwise logistic regression analysis. Main outcomes for performance of models were discrimination and calibration plots. Results. Three hundred seventy patients (47%) in the full study sample reported persistent pain at 12 weeks. The performance of the original model was poor, area under the receiver operating characteristics curve was 0.55 with a Confidence Interval of 0.51–0.59. The updated model included Radiating pain to shoulder and/or elbow, education level, physical activity, consultation-type (first- time, follow-up or maintenance consultation), expected course of neck pain, previous course of neck pain, number of pain sites, and the interaction term Physical activity##Number of pain sites. The area under the receiver operating characteristics curve was 0.65 with a 95% Confidence Interval of 0.58–0.71 for the updated model. Conclusion. The predictive accuracy of the original model performed insufficiently in the sample of patients from Norwegian chiropractors and the model is therefore not recommended for that setting. Only one predictor from the original model was retained in the updated model, which demonstrated reasonable good performance predicting outcome at 12 weeks. Before considering clinical use, a new external validation is required. Level of Evidence: 3

• Øverås, Cecilie Krage; Myhrvold, Birgitte Lawaetz; Røsok, Gro & Magnesen, Eli (2017). Musculoskeletal diagnostic ultrasound imaging for thickness measurement of four principal muscles of the cervical spine -a reliability and agreement study. Chiropractic & Manual Therapies. doi: 10.1186/s12998-016-0132-9. Full text in Research Archive

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• Vøllestad, Nina Køpke; Irgens, Pernille Marie Stähr; Myhrvold, Birgitte Lawaetz; Amundsen, Olav; Tyrdal, Mari & Robinson, Hilde Stendal (2023). Rating of current pain intensity is lower than rating of the last two wees of pain. Full text in Research Archive

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