[AIDS prevention among adolescents in school: a systematic review of the efficacy of interventions].
OBJECTIVE
Preventive interventions are considered useful although poorly evaluated. Since 1990 there are growing evidences of effective school aids prevention interventions. This paper aims to identify school aids prevention programs among youngsters aged 13 to 19, published between 1990 and 1995, to analyze each evaluation and intervention quality, to assess their effectiveness as well as identifying the possible contributing factors.


METHODS
Location of reports by means of a Medline computerized search of published articles and reviews, which should include the following criteria: school aids prevention programs, addressed to youngsters aged 13 to 19, published in Spanish, French or English between 1990 and 1995 in scientific literature, and evaluating changes in behavior or its determinants through quantitative measures. Analysis of the evaluation quality through the assessment of the sample size, the use of a control group, the groups comparability, the drop out analysis and the time between the pretest and the posttest. Intervention quality analysis through the use of a psychological behavioral change model and the number of sessions. The effectiveness of the high quality interventions in changing behaviors, intentions, attitudes and knowledge was assessed.


RESULTS
29 studies were selected. Of these studies, relating the quality of evaluation criteria, a 28% was considered a high quality study, a 14% an intermediate quality study and a 58% a low quality one. In relation to intervention quality criteria, a 27% was found to be a high quality study, a 41% an intermediate quality study and 32% a low quality one. 38% (11 studies) showed high or intermediate quality criteria at the same time in intervention and in evaluation. All these studies modified knowledge and attitudes, an 80% modified the intention to behave and a 86% modified behavior. The increase in knowledge and attitudes was in general quite important, greater than 10%, and changes in intentions and behaviors were smaller than 10%, although relevant.


CONCLUSIONS
Only 38% of the studies may be considered of high or intermediate quality. Preventive interventions correctly evaluated which rely on a theoretical model and offer 4 or more sessions show evidence of moderate but relevant reduction of aids risk practices, and important changes of the future behavior determinants.
Juárez
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Centre d'Estudis per a la Prevenció de la SIDA, Institut Municipal de Salut Pública, Barcelona, 08023, España.
Díez
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D000163:Acquired Immunodeficiency Syndrome / Q000517:prevention & control* / Q000523:psychology; D000293:Adolescent; D005260:Female; D015497:HIV-1; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D012309:Risk-Taking; D020377:Self Efficacy; D012736:Sex Education / Q000706:statistics & numerical data; D012725:Sexual Behavior / Q000523:psychology / Q000706:statistics & numerical data