Restocking the sample closet: results of a trial to alter medication prescribing.

BACKGROUND Although medication costs make up a large and growing portion of health care costs, few interventions have successfully encouraged physicians to alter prescribing patterns. METHODS To promote the use of an open formulary, we altered the contents of the sample closets of five primary care practices in eastern Massachusetts. In these practices, we removed all nonformulary drugs in five drug classes and restocked with purchased generic samples. We performed a time series analysis of formulary compliance, before and during an 8-month intervention, with five concurrent control practices for comparison. RESULTS Although providers in both the intervention and control practices complied well with the formulary, we found no incremental effect of the sample closet intervention on absolute formulary compliance (P = .46) or on the secular trend in formulary compliance (P = .60). We also found no effect on these measures in any of the individual drug classes studied. CONCLUSIONS This sample closet intervention did not appear to improve further the good formulary compliance in these practices. In such settings, better ways are needed to guide prescribing behavior.