Patient-reported medication adherence and tolerability: Results of a prospective observational study

Purpose Medication nonadherence (MNA) is a major contributor to late allograft loss in transplantation. Immunosuppression therapy is highly effective at preventing rejection yet presents a substantial toxicity burden. There is limited data assessing the correlation between MNA and tolerability in transplant. Methods This was a single-center prospective observational longitudinal study including adult transplant recipients. Consenting transplant patients were administered a survey assessing adherence (Morisky Med Adherence Survey, MMAS) and a medication tolerability assessment (modified MTSOSD-59R). Participants were emailed surveys every 2 months (repeated measures) for a maximum of 36-months. Generalized linear models (logistic and Gaussian) were used for analyses, accounting for correlation by repeated measures and time. Results There were 472 assessments completed in 268 transplant recipients. Mean post-transplant time was 4.0 +/- 5.4 years; medium or high adherence was reported in 77.4% of responses. Medication side effect burden improved over time, while medication adherence had a decreasing trend over time. Self-reported medication side effect burden significantly correlated with medication adherence. For every one-point increase in side effect burden there was a 1.3% corresponding decrease in odds of reporting medium to high adherence. Those with higher than average medication side effect burden had a 57% lower odds of reporting medium to high adherence. Conclusion MNA is common in transplant recipients, regardless of transplant type. Self-reported medication side effect burden is significantly correlated with medication adherence, offering a potential area of intervention for clinicians to improve non-adherence rates.