Psychometric Properties of Fagerström Test for Nicotine Dependence for Smokeless Tobacco Users (FTND-ST).

Abstract

Fagerström Test for Nicotine Dependence (FTND) is the most commonly used measure of dependence among tobacco users. Psychometric properties of FTND have been validated among cigarette smokers, but the reliability and validity of its variant for smokeless tobacco (ST) users (FTND-ST) is not well documented. The objective of the present study is to evaluate reliability, construct validity, and structure model of FTND-ST. Data from 95 exclusive ST users living in Oklahoma were used for this study. Participants completed a self-administered mail survey including FTND-ST and other questionnaires. Measures of internal consistency, Cronbach's coefficient α and item-total correlation were estimated to evaluate reliability of the FTND-ST. To ascertain the factor structure of the scale, confirmatory factor analysis was performed. We examined concurrent and construct validity with correlation and regression analysis. Salivary cotinine concentration was used as a criterion variable. The FTND-ST demonstrated good reliability with acceptable Cronbach's coefficient (α = 0.72) and significant item-total correlations. Study findings showed that FTND-ST had positive significant association with salivary cotinine concentration (r = 0.61, p <.0001) and Tobacco Dependence Screener (r = 0.44, p < .0001). Results of factor analysis support a unidimensional factor structure of FTND-ST. The FTND-ST demonstrated good psychometric properties. The unidimensional structure of the scale indicates that it measures single clearly defined aspect of dependence, physical dependence. Given its good reliability and demonstrated construct validity, FTND-ST is a useful measure of dependence among ST users. Because of the paucity of ST dependence research, there are limited studies evaluating ST dependence measures. Although the FTND was exclusively developed for cigarette smoking, it has been adapted for ST users in the form of FTND-ST. This is the first study to examine reliability, concurrent and construct validity, and structure model of FTND-ST among regular ST users. Findings suggest that the FTND-ST measures physical aspect of dependence. Good psychometric properties of FTND-ST and its orientation as a continuous scale indicate that FTND-ST is a useful measure of dependence among ST users.