PSYCHOMETRIC PROPERTIES OF THE IRANIAN VERSION OF THE FAGERSTROM TEST FOR NICOTINE DEPENDENCE AND OF HEAVINESS OF SMOKING INDEX

Fagerstrom test for nicotine dependence (FTND) is one of the tests widely used to measure the nicotine dependence. The shorter copy of the test is known as the heaviness of smoking index (HSI). The aim of this study was psychometric properties of Persian version of FTND and HSI in smokers. The questionnaire was assessed in terms of validity and reliability. The internal consistency and stability of the questionnaire was examined through Cronbach’s alpha and intraclass correlation coefficient (ICC). The participants were 230 smokers with mean age of 35.64 (±7.40) years. The mean score of FTND and HSI was estimated 2.38 (±1.05) and 1.06 (±0.954), respectively. In analysis of the construct validity, the exploratory factor analysis (on 130 samples) showed a factor with variance coverage of 42.73% for all items. Furthermore, the confirmatory factor analysis showed rather favorable fit for the indexes (NFI=0.92, CFI=0.95, GFI=0.93, RMSEA=0.07, χ2/ df=2.0). The Cronbach’s alpha coefficient confirmed the internal consistency (FTND=0.71 and HSI=0.68); and ICC also indicated the favorable reliability of the instruments (FTND=0.63 and HSI=0.70). The results showed that the Persian version of the instrument had favorable validity and reliability and could be used in smoking control programs in order to evaluate the cigarette dependence.