Cost-Related Medication Nonadherence in Adults with Atherosclerotic Cardiovascular Disease in the United States, 2013 to 2017

Background: Medication nonadherence is associated with worse outcomes in patients with atherosclerotic cardiovascular disease (ASCVD), a group who requires long-term therapy for secondary prevention. It is important to understand to what extent drug costs, which are potentially actionable factors, contribute to medication nonadherence. Methods: In a nationally representative survey of US adults in the National Health Interview Survey (2013-2017), we identified individuals ≥18 years with a reported history of ASCVD. Participants were considered to have experienced cost-related nonadherence (CRN) if in the preceding 12 months they reported skipping doses to save money, taking less medication to save money, or delaying filling a prescription to save money. We used survey analysis to obtain national estimates. Results: Of the 14 279 surveyed individuals with ASCVD, a weighted 12.6% (or 2.2 million [95% CI, 2.1-2.4]) experienced CRN, including 8.6% or 1.5 million missing doses, 8.8% or 1.6 million taking lower than prescribed doses, and 10.5% or 1.9 million intentionally delaying a medication fill to save costs. Age <65 years, female sex, low family income, lack of health insurance, and high comorbidity burden were independently associated with CRN, with >1 in 5 reporting CRN in these subgroups. Survey respondents with CRN compared with those without CRN had 10.8-fold higher odds of requesting low-cost medications and 8.9-fold higher odds of using alternative, nonprescription, therapies. Conclusions: One in 8 patients with ASCVD reports nonadherence to medications because of cost. The removal of financial barriers to accessing medications, particularly among vulnerable patient groups, may help improve adherence to essential therapy to reduce ASCVD morbidity and mortality.