Comparison of targeting a DUR letter intervention at pharmacists separate from and in addition to physicians

To examine the impact on dipyridamole prescribing of a letter mailed to pharmacists and/or physicians.

Interrupted time series with control series.

State of Wisconsin.

Physicians and pharmacists caring for patients who were prescribed dipyridamole.

The state of Wisconsin was divided into four sections, three of which were designated as experimental regions (letter to physician only, letter to pharmacist only, and letter to both physician and pharmacist) and one of which served as a control region.

Cost of drug per patient per month in ambulatory and long-term care populations.

For 763 long-term care and 586 ambulatory Medicaid patients, letters sent to both physicians and pharmacists resulted in significant reductions in dipyridamole expenditures relative to the control group. For long-term care patients, interventions directed at both physicians and pharmacists produced significant reductions in dipyridamole prescribing relative to interventions directed at physicians alone or pharmacists alone.

Future DUR letter interventions designed to change prescribing habits would be more effective if they targeted both physicians and pharmacists, particularly in the long-term care setting.