[Intervention strategies for the rational use of anti-microbials]

To evaluate the impact of two strategies aimed at improving the prescription of antibiotics in the primary care context.

Experimental crossed-intervention study, with control group and randomised allocation to groups.

Two primary care helth districts (Camas and Sierra Norte).

84 general practitioners for whom computerised prescription data were available, and who worked for over 40% of the working days of the study period. Interventions. In the intervention group, training sessions were conducted and written information was sent out. In the control group, only written information was sent.

The impact of the interventions was evaluated through the student´s t test for paired data. Variables were the DHD of antibiotics, selection of first-level antibiotics and %RSP of antibiotics out of total pharmaceutical cost. Secondary measurements included duration of the effect of the intervention and description of the group who responded.

In the intervention group, the DHD dropped significantly (from 17.4±1.4 to 12.2±0.9) (P<.05), as did the %RSP (from 6.96%±0.6 to 5.19%±0.8), as against the control group. The impact of the intervention lasted 1.5 years, when information was sent at one year from the intervention. The profile of the doctors who responded to the intervention was women aged 46 with MIR (residential) training.

To modify antibiotic prescription habits, training sessions accompanied by written information gives good lasting results. The profiles of respondents/non-respondents depended on sex, age and training.