Effects 4.5 years after an interactive GP educational seminar on antibiotic therapy for respiratory tract infections: a randomized controlled trial

The few studies assessing long-term effects of educational interventions on antibiotic prescription have produced conflicting results. Our aim was to assess the effects after 4.5 years of an interactive educational seminar designed for GPs and focused on antibiotic therapy in respiratory tract infections (RTIs). The seminar was expected to decrease antibiotic prescriptions for any diagnosis. We conducted a randomized controlled parallel-group trial in a Paris suburb (France), with GPs as the randomization unit and prescriptions as the analysis unit. The intervention occurred in September 2004 and the final assessment in March 2009. Among 203 randomized GPs, 168 completed the study, 70 in the intervention group and 98 in the control group. Intervention GPs were randomized to attending only a 2-day interactive educational seminar on evidence-based guidelines about managing RTIs or also 1 day of problem-solving training. The primary outcome was the percentage of change in the proportion of prescriptions containing an antibiotic for any diagnosis in 2009 versus 2004. An intention-to-treat sensitivity analysis was performed using multiple imputation. After 4.5 years, absolute changes in the primary outcome measure were -1.1% (95% confidence interval: -2.2 to 0.0) in the intervention group and +1.4% (0.3-2.6) in the control group, yielding an adjusted between-group difference of -2.2% (-2.7 to -1.7; P < 0.001). Both intervention modalities had significant effects, and multiple imputation produced similar results. A single, standardized and interactive educational seminar targeting GPs significantly decreased antibiotic use for RTIs after 4.5 years.