Relationship between choice of opioid agonist therapy and distance from patients' residences in Taiwan, 2012-2014.

Wei, Lien-Chung; Chan, Hung-Yu

BACKGROUND Choice of opioid agonist therapy (OAT) for opioid use disorder (OUD) can be impacted by variables such as age, sex, and socioeconomic status. However, it remains unknown whether accessibility of treatment affects patient choice of OAT. OBJECTIVES To investigate the association between distance to the treatment site and choice of OAT. METHODS Electronic records were collected for the last outpatient visits of individuals with OUD between January 1, 2012 and December 31, 2014. The address of each patient was processed using the Geographic Information System to obtain the distance between place of residence and the hospital. Multivariate logistic regression was used to assess the correlation between individual drug selection and distance of residence. Among the study population of 2804 patients (81.5% male), 74.1% were receiving methadone while 25.8% were receiving buprenorphine. The vast majority (95%) of all patients lived within 50 km of the hospital, so regression analysis was limited to this distance. Sensitivity analysis was estimated using robust Poisson regression. RESULTS Logistic regression revealed that every 1-km increase in distance from home to hospital increased the odds ratio of choosing sublingual buprenorphine tablets over methadone by 1.05 (p = .02, 95% confidence interval (CI) = 1.02-1.08). CONCLUSIONS Patients living closer to the treatment center were more likely to choose methadone as treatment, while patients living farther away were more likely to choose sublingual buprenorphine tablets. To mitigate the influence of travel distance on therapy choice, we recommend that more medical institutions participate in OAT services.