Effects of using free sample medications on the prescribing practices of family physicians.

INTRODUCTION We determined whether family physicians (FPs) who distribute free sample medications are more likely to prescribe those medications than physicians who do not. METHODS We reviewed administrative health plan prescription data of three similar clinics with 23 FPs within a comprehensive health care delivery system. Only clinic X physicians dispensed free sample medications. To determine which prescribed medications to study, the sample medications log from clinic X was categorized. The 25 sample medications most frequently dispensed by category were selected as study medications. Outcome measures included the number, proportion, cost, and formulary status of study medications prescribed and the average 30-day prescription costs. RESULTS Physicians at clinic X prescribed the largest proportion of prescriptions for study medications, the smallest proportion of preferred name brands among study medications, and had the highest costs for prescriptions of non-listed formulary study medications (P < .0001). The average 30-day prescription costs differed significantly by clinic (P < .0001), with clinic X being the highest. There was a significant association between the number of samples dispensed and the number of prescriptions written for study medications by physicians at clinic X (P = .006). CONCLUSIONS Our data support the conclusion that FPs who distribute free samples are more likely to prescribe those medications than their counterparts who do not.