PHS101 - Cost Analysis of Medication Therapy Management - Using Propensity Score Matching Method

Abstract

To compare total health care costs for a cohort of patients who received MTM (Medication therapy management) with controls among an eligible Medicaid managed care population. A post-hoc analysis of a retrospective observational cohort study comparing MTM to usual care. The intervention population included patients aged 18-65 who opted-in to receive MTM services (n=1,007) compared with control patients who opted-out of MTM (n=13,614). All patients were followed for 12 months before the index/enrollment date and 12 months after the index date. Total, inpatient, outpatient, emergency, and pharmacy paid healthcare claims from Medicaid during the 12-month follow-up period was collected for all patients. T-tests and Chi-squared tests were used to compare patients’ differences in baseline characteristics. Stepwise regression was used to select baseline covariates to generate a propensity score based on receipt of MTM. An 8-digits to 1-digit Greedy matching algorithm was adapted for matching cases to controls. Unadjusted difference-in-differences (DID) was used to compare the means of log transformed healthcare costs between cases and controls. After matching, the differences of baseline covariates in cases and controls were reduced by mean absolute bias of -46.8%. The matched population used for analysis included 832 cases and 1664 controls. Mean total DID healthcare costs were significantly higher among the MTM intervention cases (Δ$3,614) compared with matched controls (Δ$-413; p<0.001). Pharmacy (drug) DID costs were significantly higher among the MTM intervention cases (Δ$3,284) compared to controls (Δ$-1,303; p<0.001). Inpatient, outpatient, and emergency department DID costs were not significantly different between cases and controls. The MTM intervention for this Medicaid population increased total healthcare costs. Increasedpharmacy costs appear to drive the overall health care costs for MTM intervention.