Limited effectiveness of a school-based HIV prevention campaign in Italy. A randomized controlled trial

Abstract

Objectives: to evaluate the effectiveness of a large-scale, school-based, teacher-delivered campaign for the prevention of HIV infection. Methods: 46 junior and senior high schools in the Lazio Region of Italy were randomized to either an intervention or a control group. The corresponding study population consisted of 645 teachers and 3,866 students. The intervention followed the methods used in a large-scale, teacher-delivered campaign already implemented in the schools of the region. Questionnaires eliciting AIDS-related knowledge, attitudes and risk perceptions were administered to teachers and students in both study groups before and after the intervention. The increments in scores were analysed by a mixed model analysis of variance. Results: the average increment in the teachers' knowledge score was 4.18 points higher in the intervention group than in the control group (p<0.001). Among the students, the differential increment in favour of the intervention was only 0.9 in the knowledge section (p<0.001) and 0.58 in the risk perception section (p=0.08), adjusted for pre-test scores and sociodemographic characteristics. Greater effectiveness was observed among the students who had lower baseline knowledge and in junior high schools. Conclusions: although the large-scale preventive campaign improves the teachers' knowledge, it does little to improve the students' knowledge and risk perception. The effect appeared to be variable across the types of school. This suggests the urgency of differentiating preventive strategies, using only validated models with a proper theoretical support and calibrating the message for populations in different age and social classes.