Cost-Related Medication Nonadherence in Adults With Diabetes in the United States: The National Health Interview Survey 2013-2018.

OBJECTIVE: Health-related expenditures resulting from diabetes are rising in the U.S. Medication nonadherence is associated with worse health outcomes among adults with diabetes. We sought to examine the extent of reported cost-related medication nonadherence (CRN) in individuals with diabetes in the U.S. RESEARCH DESIGN AND METHODS: We studied adults age ≥18 years with self-reported diabetes from the National Health Interview Survey (NHIS) (2013-2018), a U.S. nationally representative survey. Adults reporting skipping doses, taking less medication, or delaying filling a prescription to save money in the past year were considered to have experienced CRN. The weighted prevalence of CRN was estimated overall and by age subgroups (<65 and ≥65 years). Logistic regression was used to identify sociodemographic characteristics independently associated with CRN. RESULTS: Of the 20,326 NHIS participants with diabetes, 17.6% (weighted 2.3 million) of those age <65 years reported CRN, compared with 6.9% (weighted 0.7 million) among those age ≥65 years. Financial hardship from medical bills, lack of insurance, low income, high comorbidity burden, and female sex were independently associated with CRN across age groups. Lack of insurance, duration of diabetes, current smoking, hypertension, and hypercholesterolemia were associated with higher odds of reporting CRN among the nonelderly but not among the elderly. Among the elderly, insulin use significantly increased the odds of reporting CRN (odds ratio 1.51; 95% CI 1.18, 1.92). CONCLUSIONS: In the U.S., one in six nonelderly and one in 14 elderly adults with diabetes reported CRN. Removing financial barriers to accessing medications may improve medication adherence among these patients, with the potential to improve their outcomes.