OBJECTIVES: Many patients face a high financial burden of medications, which may lead to poor health outcomes. The behaviors of non-adherence due to financial difficulties, known as cost-related medication non-adherence (CRN), include taking smaller doses of drugs, skipping doses, or delaying prescriptions. The objectives of this study were to 1) examine the CRN prevalence, 2) determine the impact of CRN on healthcare utilization and patient-reported outcomes, and 3) identify potential predictors for healthcare utilizations and patient-reported outcomes.

METHODS: This study was a cross-sectional study of a sample of elderly Medicare beneficiaries who reported to have used antidepressants in 2017. Patient baseline characteristics by use of antidepressants were evaluated based on Chi-square tests. Four logistic regressions were implemented to evaluate the impact of CRN, and the potential predictors of healthcare utilizations and patient-reported outcomes.

RESULTS: Antidepressant users had higher prevalence of CRN compared to non-users (1.99% vs 0.67%) (P=0.0006). For patient reported outcomes after controlling for covariates, CRN was associated with poorer patient-reported outcomes but not statistically significant: general health status (odds ratio [OR]: 0.31; 95% confidence interval [CI]: 0.09-1.10) and disability status (OR: 3.98; 95% CI: 0.97-16.30). In addition, CRN was associated with increased outpatient visits (OR: 8.815; 95% CI: 1.80-43.11), but not associated with ER visits (OR: 1.08; 95% CI: 0.30-3.85). Potential predictors for patient-reported outcomes include age, gender, race, income, region and number of comorbidities. Predictors for healthcare utilization include age, income, region, residence and number of comorbidities.

CONCLUSIONS: For elderly Medicare beneficiaries on antidepressants, CRN was higher among antidepressant users (1.99%) compared to non-users (0.67%). The healthcare provider needs to define the reasoning for CRN and consider the factors that may enhance patient-reported outcomes and healthcare efficiency. Future studies using a longitudinal research design are required to determine the cause-and-effect of the impact of CRN on healthcare utilization and patient-reported outcomes.