Modification of Reasoned Action Theory and comparison with the original version by path analysis for substance abuse prevention among adolescents

Introduction: Objective of present study was assessing the competence of self efficacy
to development of theory of Reasoned Action (TRA) and comparison with original
version by path analysis for substance abuse prevention among adolescents.
Methods: In this analytic study, 433 randomly selected adolescents (range of age 15–19)
from Tehran participated in study. The study design was based on the theory of Reasoned
Action and other self efficacy methods. Validity and reliability of the study questionnaire
was assessed. Then the collected data were analyzed by using path analysis method
Results: The results indicated that the reasoned action developed by self efficacy, has a better
fitness (RMSEA=0.043 – df /χ٢=1.77– P-value=0.1829) compare to the original
(RMSEA=0.128 – df /χ٢ =7.96 – P-value=0.00479) in path analysis. In this study self
efficacy become effective construct for fitness of model and powerful predictors for intention
(ß=0.35) and behavior (ß=0.20). The model covered 36% of intention variance and 28% of
behavior variance.
Conclusion: The reasoned action was developed by self efficacy and increased its
prediction.