Cost-related medication underuse among chronically ill adults: The treatments people forgo, how often, and who is at risk

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.