Efetividade de uma interven？？o educacional em tabagismo entre adolescentes escolares

the aim of the present study was to evaluate the effectiveness of an educational program on smoking developed by the brazilian institute of cancer among adolescents from pelotas, brazil. out of 46 public schools in the city, 32 were sampled and randomized into an intervention and a control group. in both phases of the study (pre and post intervention), 7th and 8th grade students answered to a questionnaire and had a sample of urine collected for cotinine analysis. the educational intervention lasted six months. outcome variables were: "self-reported smoking within the previous 30 days" and "cotinine concentration in urine (classified into > 10 ng/ml and > 30 ng/ml). no effects of the intervention were observed for any of the behavioral outcomes, although knowledge on the harmful effects of smoking increased in the intervention group. in summary, the intervention was not effective to produce behavioral changes, but led to an increase in the knowledge about smoking.