Antidepressant adherence and its predictors in immigrants with depression: A population-based study

Immigrants in Korea are relatively vulnerable in terms of medication self-management and have low levels of medication adherence. We aimed to evaluate antidepressant adherence and its patterns in immigrants and to identify predictors of nonadherence. In this matched cohort study using the National Health Insurance claims database, immigrants who were newly prescribed antidepressants were identified (n = 2,398). The immigrants were matched with native-born Koreans in a 1:1 ratio. Antidepressant adherence was measured by the medication possession ratio at monthly intervals. Logistic regression was performed to compare antidepressant nonadherence between immigrants and native-born Koreans, and to identify factors affecting immigrants’ nonadherence. The average medication possession ratio of immigrants was 27.1%, which was lower than that of native-born Koreans (30.9%) (P = .038). Immigrants had a lower likelihood of adherence than native-born Koreans (odds ratio [OR] 0.76, 95% confidence interval [CI] 0.3–0.92). Older age, visiting a psychiatrist for the first diagnosis of depression (OR 2.24, 95% CI 1.60–3.13), achieving appropriateness of care (OR 3.54, 95% CI 2.51–4.98), and having a usual source of care (OR 1.69, 95% CI 1.25–2.27) were associated with a higher likelihood of adherence in immigrants. This study showed that antidepressant adherence of immigrants was lower than that of native-born Koreans. However, it appears that visiting a psychiatrist, achieving appropriateness of care, and having a usual source of care might increase antidepressant adherence among immigrants. Further research that focuses on cultural and/or linguistic factors affecting immigrants’ adherence and healthcare utilization is suggested as a way to increase adherence.