Introduction: The Fagerström Test for Nicotine Dependence (FTND), modified from Fagerström Tolerance Questionnairre (FTQ), is used to determine whether a smoker trying to quit will need nicotine replacement therapy to treat with drawal symptoms. The FTND has been translated into many languages and has been referred to in the smoking literature worldwide. However, only a few studies have examined the psychometric propertiesof the non-English FTND versions. This study aimed to assess the psychometric properties of the Turkish version of the FTND.
Materials and methods: Confirmatory factor analysis (CFA) was used to test the factor structure of the Turkish version of the questionnaire using a large sample from two smoking cessation clinics in Istanbul, Turkey. Our study comprised 502 smokers who entered one of these smoking cessation clinics between October 1 and December 31, 2011. All subjects gave informed consent to the study. We assessed the validity of the FTND using CFA, and we calculated Cronbach's alpha coefficients to determine reliability.
Result: One-factor CFA included all of the items on the FTND. All items loaded on this factor with a score of 0.40 or higher. The goodness of fit statistics were adequate, with a Comparative Fit Index (CFI) of 0.922, a Tucker-Lewis Index (TLI) of 0.902, and a root-mean-square error of approximation (RMSEA) of 0.081. Two-factor CFA comprised the three "morning smoking" items, and the three "smoking pattern" items. The factor loadings and the goodness-of-fit statistics confirmed that the FTND has a two-factor structure.
Conclusions: Analyses confirmed that the Turkish version of the FTND has a two-factor structure with moderate reliability. This study found that using a total score as an estimate of nicotine dependence may limit the assessment of specific smoking dependency and tailoring intervention approaches. We suggest that a two-factor FTND in clinical practice would more accurately determine the nicotine dependence of patients.