Medication Adherence, Health Care Utilization, and Spending Among Privately Insured Adults With Chronic Conditions in the United States, 2010-2016

Background Chronic conditions are common and costly for older Americans and for the health system. Adherence to daily maintenance medications may improve patient health and lead to lower health care spending. Methods To identify predictors of adherence and to quantify associations with health care utilization and spending among older adults with chronic conditions, we conducted a longitudinal retrospective analysis using the OptumLabs Data Warehouse. This database of deidentified administrative claims includes medical and eligibility information for more than 200 million commercial and Medicare Advantage enrollees. We identified adults age 50+ years initiating treatment for atrial fibrillation (N = 33,472), chronic obstructive pulmonary disease (COPD; N = 44,130), diabetes (N =76,726), and hyperlipidemia (N= 249,391) between January 2010 and December 2014. We assessed adherence, health care utilization, and spending during the first 2 years of treatment. Results During the first year of treatment, 13%-53% of each condition cohort was adherent (proportion of days covered ≥0.80). White race, Midwest residence, and having fewer comorbidities consistently and independently predicted adherence among enrollees initiating treatment for chronic obstructive pulmonary disease, diabetes, and hyperlipidemia. Male sex and higher net worth were also independently associated with adherence among commercial enrollees with these conditions. Patients in most condition cohorts who were adherent to treatment had significantly lower odds of hospitalization or emergency department use compared to patients who were not adherent. Additional spending on pharmacy claims by patients who were adherent was not consistently offset by lower spending on medical claims over a 2-year horizon. Conclusions Although many patient factors are strongly associated with medication adherence, the problem of non-adherence is common across all groups and may increase risk of adverse health outcomes.