Objectives: We sought information about the cost-related underuse of medications-which medications are underused, by whom, and how often.
Methods: Chronically ill adults were asked to identify how often they underused prescription medication for 16 health conditions because of the cost.
Results: Eighteen percent of respondents cut back on medication use owing to cost in the previous year, and 14% used less medication at least monthly. Although rates of underuse varied substantially across treatments, prescription coverage and out-of-pocket costs were determinants of underuse across medication types.
Conclusions: Many chronically ill adults frequently cut back on medications owing to cost. Patients are selective about the treatments they forgo. Out-of-pocket costs and inadequate prescription coverage may lead to adherence problems for many important medication types.