Payesh
2010; 9: 39-49
Accepted for publication: 20 October 2008
[EPub a head of print-7 March 2010]

Objective(s): To assess the effect of processes of change on resistance skills against substance abuse among petrochemical workers in Assaluyeh Plant in Iran.
Methods: This was an experimental study (randomized intervention trial). In all 181 workers of petrochemical company in Assaluyeh were enterd into the study (90 participants in intervention group and 91 participants in control group). Data were collected by a questionnaire that was designed and validated by the researchers based on the Trans Theoretical Model (TTM).
Both groups were interviewed before the intervention, based on which the educational needs were identified. One of the diagnostic surveys showed lack of resistance skills against substance abuse that required further education. To meet this requirement a TTM based education for intervention was applied.
Results: The study showed significant improvement in most of the resistance skills among the  intervention group, while both groups showed no significant differences in use of processes of change before the intervention (except for construct self revolution, that was higher in control group). The results after the intervention showed that intervention group had used all elements of processes of change (except dramatic relief).
Conclusion: This study showed that processes of change in the TTM would lead to improved knowledge, attitude, self efficacy and self control. It also confirmed that the training materials based on the trans theoretical model can develop resistance skills against substance abuse that will ultimately result in a better health among the workers and could create a drug free workplace (safe workplace). Based on these findings the investigators recommend that all studies on health–related change behavior should continually use the behavioral theories and models.