Introduction and aims: Despite medication collection adherence being vital to both successful treatment outcomes and the prevention of overdose in treated opiate users, there are currently insufficient data on actual rates of collection adherence in this patient group. This study sought to determine the percentage of FP10MDA medication doses collected in accordance with the prescribed collection regimen among opiate users treated with methadone or buprenorphine in UK treatment services.
Methods: A 3-month cross-sectional survey across five national Change Grow Live substance misuse treatment services. Data were collected on actual collection vs. that prescribed; to establish the collection adherence rate; and carry out a descriptive analysis of collection adherence (using available demographic, clinical and risk characteristics).
Results: The mean collection adherence rate was 93% (95% CI 91, 96, median 100%, IQR 8); the majority (52%) had optimal (100%) collection adherence rates throughout the 3-month study period. Using a logistic regression analysis, poor collection adherence was predicted by other markers of risk, including injecting status, use of illicit opiates, and adjunctive stimulant use. Poor adherence was also predicted by receipt of supervised consumption and treatment with methadone. These predictors were associated with risk markers themselves, in logistic regression analyses (use of illicit opiates and alcohol, in the case of supervised consumption, and use of illicit opiates and stimulants, in the case of methadone treatment).
Conclusions: Poor adherence is predicted by markers of risk measured within this study and may be associated with additional unmeasured indicators of risk. Study findings suggest that interventions targeted specifically at opiate users with a high risk of poor adherence (injectors, on-top opiate users, adjunctive stimulant users and those on supervised consumption) to improve collection adherence are required. Long-acting buprenorphine preparations and contingency management are two interventions with the potential to improve adherence in the UK treatment setting.