Abstract
Objective
Limited research exists on how preexisting comorbidities impact retention in opioid agonist treatment (OAT). This study aimed to (1) describe OAT retention and participation, and (2) examine the association of preexisting comorbidities and other patient characteristics with 24-month retention.
Methods
This registry-based nationwide cohort study used linked health records of 1,553 individuals newly initiating OAT in the Czech Republic between 2011 and 2017. Logistic regression assessed the relationship between mental disorders, hepatitis C (HCV), Charlson Comorbidity Index (CCI), age, sex, and type of OAT medication and retention.
Results
At 24-month follow-up, less than half of patients (44.9% of men and 47.0% of women) remained in continuous treatment. Interrupted treatment occurred in 11.0% of men and 13.2% of women, while 42.0% and 39.4%, respectively, discontinued after a single episode. The mean treatment duration was 489 ± 272 days for men and 498 ± 273 days for women, corresponding to mean participation of 67.0% and 68.2%, respectively. Methadone use was associated with lower retention compared with buprenorphine (aOR = 0.46, 95% CI = 0.35–0.62). Higher CCI (OR = 0.85, 0.76–0.94) and HCV (OR = 0.67, 0.53–0.86) were associated with lower retention in crude models, but lost significance after adjustment. Other comorbidities had no effect on OAT retention.
Conclusions
Preexisting mental and physical comorbidities did not significantly affect OAT retention, though their high prevalence warrants clinical attention. Lower retention among patients receiving methadone raises public health, clinical, and ethical concerns regarding restrictive OAT regimes in the Czech Republic.
Citation
Rolová, G., Skurtveit, S., Mravčík, V., & Gabrhelík, R. (2025). Preexisting morbidity and 2-year treatment retention in opioid agonist treatment. A population-based data-linkage study in the Czech Republic. Addiction Research & Theory, 1–11. https://doi.org/10.1080/16066359.2025.2605955