A CONTROLLED LETTER INTERVENTION TO CHANGE PRESCRIBING BEHAVIOR - RESULTS OF A DUAL-TARGETED APPROACH

Objective. To determine the effectiveness of a drug utilization review (DUR) letter intervention sent only to physicians, sent only to pharm acists, or sent to both physicians and pharmacists in changing physici an prescribing behavior for dipyridamole. Data Sources/Study Setting. A Wisconsin Medicaid prescription drug database for data from March 19 91 through May 1992 related to both long-term care and ambulatory pati ent settings. Study Design. The effects of a DUR letter intervention w ere tested using a field study, pre-post, nonequivalent control group, quasi-experimental design. The effects of the letter intervention in terms of dipyridamole expenditures (dollars reimbursed to pharmacies b y Medicaid), expenditures for related drugs (aspirin, ticlopidine, sul finpyrazone) and numbers of patients for whom dipyridamole was discont inued were examined across three experimental groups and a control gro up. Data Collection/Extraction Methods. Dipyridamole expenditures for each study patient during a six-month preintervention and six-month po stintervention period were collected from Medicaid prescription drug c laims. Patients who had zero dipyridamole expenditures throughout the six-month postintervention period were classified as having had dipyri damole discontinued. Principal Findings. Letters sent to both physicia ns and pharmacists resulted in a greater percentage of patients discon tinuing dipyridamole relative to controls and statistically significan t differences in postintervention dipyridamole expenditures relative t o controls in both the long-term care and ambulatory patient populatio ns. Conclusions. Interventions that focus on another person in the dru g use process in addition to the physician may have greater effects on a change in the prescribing of a targeted drug than letters to physic ians alone.