Effectiveness of an educational intervention based on theory of planned behavior to reduce intentions to smoke among secondary school students

Beliefs about smoking are considered important predictors of smoking behavior among adolescents. the aim of the current study was to evaluate an educational program based on theory of planed behavior (tpb) at reducing intentions to smoke among adolescents. in a quasi-experimental, 150 students were selected using multistage sampling procedure from boy-specific high schools in qazvin and were randomly assigned either experimental (n=75) or control group (n=75). a self constructed questionnaire was administered consisting of demographic and the theory of planned behavior (tpb) constructs (i.e. attitudes towards smoking, subjective norms, perceived behavioral control and intention to smoke. the educational program was developed based on results arose from pretest and was delivered on the experimental group within four sessions. the randomization unit was the school. both experimental and control groups were followed up after three months of educational intervention. data was collected before and three months after the educational intervention and then inputted into spss-16 and were analyzed using descriptive analyses, chi square test, mann-whitney test, wilcoxon test and independent t-test. the educational intervention resulted in improving for attitudes, subjective norms, perceived behavioral control and intention in the experimental group. while, in the control group, there was no significant improvement in terms of the tpb constructs. the results suggest that an intervention based on the tpb could be reduced intentions to smoke among students and to prevent smoking behaviors can bring about promising results among adolescents and preventive strategies based on the tpb can be used to designing of schoolbased programs.