Supplementary Material for: Regimen Complexity and Prescription Adherence in Dialysis Patients

Objectives: Poor medication adherence is common in end-stage renal disease and may cause suboptimal outcomes and increased healthcare costs. We assessed the association between regimen complexity, perceived burden of oral therapy (BOT) and medication adherence in a large sample of hemodialysis (HD) patients. Methods: 1,238 HD patients in 54 Italian centers participated. Data were collected on patients’ socio-demographic characteristics, perceived BOT, quality of life, healthcare satisfaction, social support and medication adherence with a self-administered questionnaire. Data on medication regimen, comorbidities, hospitalizations, and transplant listing status were provided by the nursing staff. We estimated the adjusted association of regimen complexity, BOT and medication adherence with logistic regression. Results: There were 789 (64%) men and the median age was 67 years. Mean daily burden was 9.7 tablets and 48% of patients were adherent to medication prescriptions. The number of tablets prescribed in the medication regimen was associated to adherence likelihood after adjustment for possible confounders. Perceived BOT moderated the association between tablet count and self-reported adherence. Conclusion: Poor adherence was very common in our sample. Reducing tablet burden might help patients be adherent. However, our results suggest that modulating regimen complexity might be ineffective if patients’ negative attitudes toward medications are not addressed concurrently.