Controlling prescription drug expenditures: a report of success

To determine whether a multi-interventional program can limit increases in prescription drug expenditures while maintaining utilization of needed medications.

Quasi-experimental, pre-post design.

The program included formulary changes, quantity limits, and mandatory pill splitting for select drugs implemented in phases. We assessed the short-term effects of each intervention by comparing class-specific drug spending and generic medication use before and after benefit changes. Long-term effects were determined by comparing overall spending with projected spending estimates, and by examining changes in the planwide use of generic medications over time. Effects on medication utilization were assessed by examining members' use of selected classes of chronic medications before and after the policy changes.

Over 3 years, the plan and members saved $6.6 million attributed to the interventions. Most of the savings were due to the reclassification of select brand-name drugs to nonpreferred status (estimated annual savings, $941,000), followed by the removal of nonsedating antihistamines from the formulary (annual savings, $565,000), and the introduction of pill splitting (annual savings, $342,000). Limiting quantities of select medications had the smallest impact (annual savings, $135,000). Members' use of generic medications steadily increased from 40% to 57%. Although 17.5% of members stopped using at least 1 class of selected medications, members' total use of chronic medications remained constant.

A combination of interventions can successfully manage prescription drug spending while preserving utilization of chronic medications. Additional studies are needed to determine the effect of these cost-control interventions on other health outcomes.