CV1: THE VALUE OF COMPLIANCE: EVIDENCE FROM TWO PATIENT COHORTS

Abstract

OBJECTIVES: To identify the association between compliance and the direct costs of care for two different clinical patient cohorts. METHODS: Using administrative claims data from Medstat MarketScan (tm) we assessed the association between prescription drug compliance and direct costs of care for two patient groups: a cohort of non-Medicare patients diagnosed as diabetics (N = 9960) and second cohort of non-Medicare patients diagnosed with congestive heart failure (CHF)(N = 935). Since patients who are more compliant tend to be older and have a greater number of comorbidities, and our goal was to isolate the association between compliance and medical care costs, we statistically controlled for differences in potential confounding variables using OLS regression. Covariates included age, gender, comorbidity indices (Chronic Disease Score and Charlson-Deyo), and ICD-9-based severity of illness indicators. Compliance was defined by calculating % days supply over a period of one year. Compliance was then converted to 7 ordinal categories in the regression model in order to identify dose-response associations or threshold/inflection points. RESULTS: Among diabetics, those who did not use any prescription medication showed the lowest total costs of care. However, among those patients who needed prescription medication to manage their illness, increased prescription drug costs among the most compliant are more than offset by decreases in medical care costs, for an estimated return on investment (ROI) of more than two-fold. A similar, but stronger, pattern was found among patients with CHF where the estimated ROI was three-fold or greater. CONCLUSIONS: For some medical conditions, the additional costs associated with increased compliance may be offset by lower medical costs, resulting in an ROI greater than one.