Psychometric properties of the Iranian version of the fagerstrom test for nicotine dependence and of heaviness of smoking index

The most widely used tests for measuring nicotine dependence is the Fagerstom Test for Nicotine Dependence (FTND). The Heaviness of smoking index (HSI) is a shorter version of FTND. The current study aimed to asses the psychometric properties of the Persian version of the FTND and HSI for Iranian smokers. This was a descriptive- correlational study. The validity of instrument was evaluated. The internal consistency and stability of the questionnaire was tested using Cronbach’s alpha coefficient and Intraclass Correlation Coefficient (ICC). In the current study, 230 male smokers participated with mean age 35.64( ± 7.40) years. The mean of the FTND and HIS were 2.38 (±1.05) and 1.06 (± 0.954) respectively. The Exploratory factor analysis (N=130) extracted one factor that jointly account for 42.73% of variance observed. The results obtained from confirmatory factor analysis (N=100) revealed that the data was fit to the model (χ2/df =2.0, p< 0.001, RMSEA =0.07, GFI = 0.93, CFI =0.95, NFI=0.92). The Cronbach’s alpha indicated the acceptable results (FTND= 0.71 HIS= 0.68) and the ICC corresponded to the satisfactory findings (FTND= 0.63 HIS= 0.70). The findings of this study indicated the Iranian version of the instrument had satisfactory psychometric properties and could be applied in tobacco control programs to asses nicotine dependence.