[Impact of an informative feedback process on drug prescription]

To evaluate the impact of the face-to-face interview and feed-back on the prescribing habits of doctors interviewed.

Controlled intervention study.

Primary Care area (PCA) of Alt Penedès-Garraf.

16 general practitioners (GP). The intervention group (IG) consisted of 8 GPs from the county of Garraf; the control group (CG), of 8 from the Alt Penedès.

The target doctors were identified by quantitative analysis of GP prescription in the PCA in 1993. In June 1994, there was a face-to-face interview with the IG doctors. There was no intervention on the CG.

No statistically significant differences were found, for the overall prescription turnover or expenditure generated by the prescriptions, between the two groups in the pre-intervention period (p > 0.05). Drugs expenditure decreased in the IG versus an increase in the CG. Comparison of the monthly accumulated increase revealed containment of drugs expenditure during the 9 months after the interview in the IG against the growth in the CG. In addition the number of units of medicine of doubtful efficacy (UDE) and unwarranted combinations of medicine to combat infection (UCMI) prescribed per doctor went down in the IG, but went up in the CG.

The results show a containment in the growth of drug expenditure and a decrease in UDE and UCMI prescription by GPs in the IG as against the CG. The decreasing effectiveness over time of the one-off intervention suggests that there should be regular interventions to ensure a long-term effect.