Effectiveness evaluation of the school-based drug prevention program #Tamojunto in Brazil: 21-month follow-up of a randomized controlled trial.

INTRODUCTION: A school-based randomized controlled trial was conducted in 2014/2015 with students in 7th and 8th grades in 72 public schools in 6 Brazilian cities. A total of 5028 students were linked (75, 7%) in at least one of the two waves of follow-up (9 months and 21 months later). The principal research question was whether this 12-lesson program delays the initiation of alcohol, tobacco, inhalants and binge drinking among early adolescents when compared to usual care, that is, no prevention program in Brazilian schools, after 21 months of follow up.

METHODS: Cox regression models were adjusted to evaluate the incidence of drug use. Generalized linear latent mixed models (GLLAMM) were used to evaluate changes in the prevalence of each drug over time and between groups. Findings The incidence analysis showed a negative effect of the program for alcohol initiation (aHR = 1.13, 95%CI 1.01; 127) but an opposite protective effect for the initiation of inhalant use (aHR = 0.79, 95%CI 0.66; 0.95). After 21 months, the prevalence of past-year use of alcohol changed from 30.1% to 49.8% in the intervention group and from 29.9% to 45.8% in the control group. Adolescents in the intervention group were 30% more likely to have reported past-year use of alcohol than students in the control group at 21 months (aOR = 1.30, 95%CI 1.02; 1.65). No effects of the program on past-month drug use were found. The Brazilian version of the Unplugged program may be misinterpreted by public school students, perhaps arousing their curiosity regarding alcohol use.