Assessment of the Tobacco Dependence Screener Among Smokeless Tobacco Users

Introduction: Variants of the Fagerstrom Tolerance Questionnaire and Fagerstrom Test for Nicotine Dependence (FTND) are widely used to study dependence among smokeless tobacco (ST) users. However, there is a need for a dependence measure which is based on the clinical definition of dependence and is easy to administer. The Tobacco Dependence Screener (TDS), a self-administered 10-item scale, is based on the Diagnostic and Statistical Manual, fourth edition (DSM-IV) and ICD-10 definitions of dependence. It is commonly used as a tobacco dependence screening tool in cigarette smoking studies but it has not been evaluated for dependence in ST users. The purpose of this study is to evaluate the TDS as a measure of tobacco dependence among ST users. Methods: Data collected from a community-based sample of exclusive ST users living in Oklahoma (n = 95) was used for this study. TDS was adapted to be used for ST dependence as the references for smoking were changed to ST use. Concurrent validity and reliability of TDS were evaluated. Salivary cotinine concentration was used as a criterion variable. Overall accuracy of the TDS was assessed by receiver's operating characteristic (ROC) curve and optimal cutoff scores for dependence diagnosis were evaluated. Results: There was no floor or ceiling effect in TDS score (mean = 5.42, SD = 2.61). Concurrent validity of TDS as evaluated by comparing it with FTND-ST was affirmative. Study findings showed significant association between TDS and salivary cotinine concentration. The internal consistency assessed by Cronbach's alpha indicated that TDS had acceptable reliability (alpha = 0.765). TDS was negatively correlated with time to first chew/dip and positively correlated with frequency (number of chews per day) and years of ST use. Results of logistic regression analysis showed that at an optimal cutoff score of TDS 5+, ST users classified as dependent had significantly higher cotinine concentration and FTND-ST scores. Conclusions: TDS demonstrated acceptable reliability and concurrent validity among ST users. These findings are consistent with the results of previous cigarette smoking studies evaluating TDS. A self-administered tobacco dependence measure for ST users based on a clinical definition of dependence is an effective tool in research setting. Implications: ST dependence research is still evolving. This is the first study of the TDS among ST users providing preliminary evidence about some of the psychometric properties of the scale. Similar to cigarette smokers, TDS is an effective measure of ST dependence. Study showed moderate reliability and affirmative concurrent validity of the TDS among ST users.