Effects of benefit design change across 5 disease states.

OBJECTIVE: To assess the effects of benefit design change (BDC) on medication adherence and persistence (including switch in therapy), drug costs, and total healthcare costs. STUDY DESIGN: A retrospective study was performed using administrative claims data from an integrated healthcare system between January 2001 and December 2002. METHODS: Continuously enrolled patients in 2001 and 2002 with allergic rhinitis, asthma, diabetes mellitus, hypertension, or osteoarthritis belonged to employer groups with or without a pharmacy BDC as of January 1, 2002. Prescription status (same, switch, or discontinue), adherence among patients receiving therapy, and differences in drug costs and total healthcare costs for each disease state were measured between groups. Bivariate and multivariate statistics were used to test differences in outcomes between groups. RESULTS: Compared with the group without BDC, the proportion of patients who discontinued drug therapy was significantly greater in the BDC group among those with allergic rhinitis (67% vs 54%), asthma (66% vs 50%), osteoarthritis (61% vs 36%), and hypertension (39% vs 18%) (P < .05 for all). Medication compliance was not affected by BDC. The year-to-year pharmacy costs per patient in the BDC group decreased $305 for patients with osteoarthritis (P < .001) and $95 for patients with allergic rhinitis (P = .03). There was no significant effect on overall healthcare costs in any disease state during the year following the BDC. CONCLUSION: A pharmacy BDC may result in decreased pharmacy costs, with no effect on overall healthcare costs within 1 year for patients with allergic rhinitis, asthma, hypertension, or osteoarthritis.