Measuring nicotine dependence among smokeless tobacco users

The objective of this study was to assess the concurrent validity of the FTQ-ST and the DIS-IV diagnosis of nicotine dependence among 68 adult ST users enrolled in a randomized, controlled clinical trial of bupropion SR. FTQ-ST scores were not found to differ between those with and without a current DIS-IV diagnosis of nicotine dependence (7.4 ± 2.1 vs. 6.8 ± 2.8, P = 0.325). For all possible FTQ-ST cutoff scores, the observed agreement between the FTQ-ST and the DIS-IV was not found to be different from that expected due to chance. FTQ-ST total scores were positively correlated with serum cotinine (Spearman's r = 0.40, P < 0.001), amount of tobacco used (r = 0.51 and r = 0.41 for average dips/chews per day; average tins/pouches per week, respectively, P < 0.001), and a reduced likelihood of abstinence at 3 months (OR = 0.76, 95% C.I. 0.61–0.96; P = 0.019). Participants meeting DIS-IV criteria had lower cotinine concentrations than those without this diagnosis (411 ± 263 ng/ml vs. 493 ± 246 ng/ml; P = 0.042). Poor concordance was observed between the FTQ-ST and the DIS-IV in the assessment of nicotine dependence in ST users.