Drug affordability and prescription noncompliance in the United States: 1997-2002

Abstract

Background: Prescription drug costs have risen rapidly since the mid-1990s. Inability to pay for medications has consequences for population health and health system costs. However, national data on the scope of prescription noncompliance due to cost are surprisingly inconsistent.

Objective: The goals of this study were to use data from a large, all-ages survey that accurately represents the civilian, noninstitutionalized population to estimate the national prevalence of medication noncompliance due to cost, identify sources of variation in rates of noncompliance due to cost, and assess changes in these rates over a recent 6-year interval (1997-2002).

Methods: We undertook a trend analysis of the National Health Interview Surveys for 1997 through 2002 and detailed subpopulation analysis of the 2002 survey to determine rates of noncompliance due to cost.

Results: Our analyses used a total sample size of 276,425 respondents for the 6-year period and a sample size of 43,568 respondents for the year-2002 subpopulation analysis. Self-reported rates of noncompliance due to cost grew from 4.7% in 1997 to 5.9% in 2002. The results of the 2002 survey suggested that noncompliance varied by subpopulation, with relatively high rates (P < 0.001) among working-age adults (ie, aged 18-64 years), women, blacks, Medicaid and Medicare beneficiaries, those with low incomes, and those without health insurance.

Conclusion: A relatively small but growing proportion of Americans are unable to afford the medications they are prescribed. Cost-associated noncompliance, like other health care access problems, is unevenly distributed in the population.