Background: Chronic pulmonary diseases (CPDs) such as asthma and COPD are associated with particularly high rates of cost-related medication nonadherence (CRN), but the degree to which inhaler costs contribute to this is not known. Here, we examine the relationship between inhaler-specific out-of-pocket costs and CRN in CPD.
Methods: Using data obtained in 2006 in a national stratified random sample (N = 16,072) of community-dwelling Medicare beneficiaries aged >or= 65 years, we used logistic regression to examine the relationship between inhaled medications, various types of out-of-pocket costs, and CRN in persons with CPD.
Results: The prevalence of CRN in Medicare recipients with CPD using inhalers was 31%. In multivariate models, the odds that respondents with CPD using inhalers would report CRN was 1.43 (95% CI, 1.21-1.69) compared with respondents without CPD who were not using inhalers. Adjustment for out-of-pocket inhaler costs-but not adjustment for total medication costs or non-inhaler costs-eliminated this excess risk of CRN (OR, 0.95; 95% CI, 0.71-1.28). Patients paying > $20 per month for inhalers were at significantly higher risk for CRN compared with those who had no out-of-pocket inhaler costs.
Conclusions: Individuals with CPD and high out-of-pocket inhaler costs are at increased risk for CRN relative to individuals on other medications. Physicians should be aware that inhalers can pose a particularly high risk of medication nonadherence for some patients.