Abstract
INTRODUCTION: In recent years, waterpipe smoking (WPS) has increased among adolescents in Iran. This study aimed to explain the experiences of high school students in Iran on predictors of WPS reduction based on a multi-theory model (MTM) of health behaviour change. METHODS: This study was a qualitative study of directed content analysis that was conducted in high school male students in Hamadan, Iran, in 2017. In this study, 34 students who had smoked waterpipe (WP) in the last month were recruited through snowball sampling that was continued until data saturation. The data were collected through semi-structured, individual interviews and were then analyzed using directed qualitative content analysis. RESULTS: The data analysis resulted in the extraction of 104 final codes around the six themes of predetermined MTM constructs consisting of participatory dialogue, behavioural confidence, changes in the physical environment, emotional transformation, practice for change, and changes in the social environment. The findings of this study showed that this model has the potential to explain the behaviour of WPS reduction. The main predictors of reduction in WPS are behavioural confidence, social environment change, and participatory dialogue. CONCLUSIONS: Findings of the research showed that the belief in an individual's ability, support from friends and the benefits of WPS reduction are the most important factors in reducing WPS among students. Therefore, it is suggested that comprehensive interventions be developed to improve the individual and social factors that are effective in WPS reduction.