Mediating roles of medication-taking self-efficacy and depressive symptoms on self-reported medication adherence in persons with HIV: A questionnaire survey

Background: To date, only a few studies have examined the mediating role of self-efficacy on the relationship between depressive symptoms or perceived social support and medication adherence in persons with HIV. Objectives: The purpose of this study was to examine the impact of perceived social support, depressive symptoms and medication-taking self-efficacy on self-reported medication adherence in persons with HIV. A proposed comprehensive model included three mediation hypotheses in order to examine the mediating roles of medication-taking self-efficacy and depressive symptoms. Method: Baseline data from "Adherence to Protease Inhibitors" were used. The 215 persons with HIV aged 19-61 (mean = 40.7, S.D. = 7.58) were recruited from multiple sites in Pittsburgh, PA (USA) and through self-referral. The participants were assessed using the Beek Depression Inventory, Interpersonal Support Evaluation List, the Medication Taking Self-Efficacy Scale, and the modified Morisky Self-report Medication Taking Scale. Structural equation modeling (EQS version 6.1) was used. The Satorra-Bentler Scaled test statistics (S-B chi(2)), Comparative Fit Index (CFI), and the Standardized Root Mean Squared Residual (SRMR) were used to assess the fit of a comprehensive model including three mediation hypotheses. Results: A comprehensive model with the three hypotheses showed a good model fit (S-B chi(2) (24, N = 215) = 69.06, p <.001; CH =.95; SRMR =.057). Medication adherence self-efficacy fully mediated the prediction of self-reported medication adherence by perceived social support and depressive symptoms. Depressive symptoms partially mediated the prediction of medication-taking self-efficacy by perceived social support. Conclusions: The findings of this study provide researchers with increased understanding of the mediating role of medication-taking self-efficacy beliefs between selected psychological variables and self-reported medication adherence