Development and psychometric validation of substance abuse prevention questionnaire based on the multi-theory model: construct validity and reliability

Substance abuse is one of the major social challenges worldwide. To address this issue, health promotion specialists are striving to overcome the limitations of existing health education models in promoting unhealthy behaviors. The relatively new Multi-Theory Model (MTM) has been introduced as a framework for changing unhealthy behaviors. However, no valid questionnaire based on this model is currently available for the prevention of substance abuse. Accordingly, the present study was conducted to develop and psychometrically evaluate a questionnaire based on the Multi-Theory Model for the prevention of substance abuse.

This cross-sectional study was conducted in 2024 among 280 residents of the Akramieh neighborhood in Yazd, Iran. Participants were selected using a systematic sampling method. Based on a review of the existing scientific literature and a qualitative study, a measurement instrument was developed. The validity and reliability of the instrument were evaluated by an expert panel, and indices such as the Content Validity Ratio (CVR), Content Validity Index (CVI), face validity, factor analysis, internal consistency, convergent validity, and Cronbach's alpha were calculated. Data analysis was performed using SPSS and R software.

Among the various constructs of the Multi-Theory Model (MTM), the construct with the highest factor loading was "change in the social environment" (27.41%). It was followed by "participatory dialogue: advantages" (9.58%) and "emotional transformation" (7.98%). The other constructs, in descending order of factor loading, included "change in the physical environment" (5.95%), "participatory dialogue: disadvantages" (4.10%), "behavioral confidence" (3.35%), and "practice for change" (3.16%). The model fit indices for the first-order model were as follows: CMIN/DF = 1.168, NFI = 0.955, RMSEA = 0.021, CFI = 0.993, TLI = 0.993, GFI = 0.968, IFI = 0.993. For the second-order model, the indices were: CMIN/DF = 1.624, NFI = 0.937, RMSEA = 0.040, CFI = 0.975, TLI = 0.973, GFI = 0.955, IFI = 0.975. Both models demonstrated a satisfactory level of goodness of fit.

The findings of this study provide strong evidence for the factorial structure and reliability of the developed measurement instrument. They demonstrate that the constructs of the Multi-Theory Model (MTM) can be effectively measured through a rigorous psychometric process for the prevention of substance abuse. The results indicate that the developed questionnaire is useful for predicting related factors and designing preventive interventions in the field of substance abuse. Further studies aimed at optimizing the application of the MTM and organizing its constructs within the dual phases of initiation and sustenance would enhance the theoretical richness of the model.