Drug Abstinence Self-Efficacy Scale (DASES): psychometric properties of the Farsi version

Research has demonstrated that therapeutic interventions based on the self-efficacy theory produce positive outcomes for people who exhibit addictive behaviors, such as alcohol and drug use. Several questionnaires based on self-efficacy theory have been developed to evaluate the extent to which intervention programs can modify behavior. The present study describes the psychometric properties of the Farsi version of the Drug Abstinence Self-Efficacy Scale (DASES).

The forward-backward approach was employed to translate the DASES from English into Farsi. A cross-sectional study was conducted, and the psychometric properties of the Farsi version of the DASES were measured. Using a cluster sampling method, 400 male people who use drugs aged 20 years or older were selected from 10 addiction treatment clinics in Mazandaran, Iran. The internal consistency and test-retest methods were used to measure the reliability of the DASES. Face and content validity were measured, and the construct validity of the DASES was assessed through both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The data were analyzed using SPSS and AMOS.

The results of the EFA indicated a four-factor solution for the DASES that accounted for 64.72% of the observed variance. The results obtained from the CFA demonstrated that the data fitted the model: the relative chi square (× 2/df) equaled 1.99 (p < 0.001), and the root mean square error of approximation equaled 0.071 (90% CI = 0.059-0.082). All the comparative indices of the model were equal to or greater than 0.90 (0.91, 0.93, 0.94, 0.93, and 0.90, respectively). The Cronbach's alpha ranged from 0.90 to 0.93, proving a satisfactory reliability. Additionally, the intraclass correlation coefficient ranged from 0.75 to 0.98, which is an acceptable result.

This study's results show that the Iranian version of the DASES has good psychometric properties and is appropriate for assessing substance use behaviors among Iranian addicted persons.