Measuring tobacco dependence in the general population: Evaluation of the Cigarette Dependence Scale (CDS-12) and its adaptation to smokeless tobacco use (STDS-12) in two Swedish surveys.

Abstract

The 12-item Cigarette Dependence Scale (CDS-12) is an instrument suitable to assess tobacco dependence in non-clinical populations. The aim of this study was twofold: a) to evaluate the scale's performance in a smoking population including non-daily smokers; b) to explore the scale's adaptation to the assessment of dependence on smokeless tobacco. In a cross-sectional study we investigated performance and construct validity of the CDS-12 and of its adaptation to smokeless tobacco (STDS-12) in two Swedish population samples. The first sample consisted of young adults (1246 ever daily smokers and 1086 ever daily snus (the Swedish type of moist oral snuff) users between 19 and 28 years of age). The second sample included 1229 current smokers and 855 current users of snus between 16 and 84 years of age. Score distribution, internal consistency, factor structure, and associations with other indicators of tobacco dependence were analysed. Both scales had a small amount of missing answers (below 2% in most items) and had acceptable internal consistency. Factor analyses suggested a one-factor model. CDS-12 score and proportions classified as dependent were significantly higher among daily smokers compared to non-daily smokers, positively correlated with the number of cigarettes, and negatively with quit attempts as well as their duration. The same pattern was seen for STDS-12, apart from correlation with quit attempts. Both the CDS-12 and its adaptation to smokeless tobacco, tested for the first time in this study, appear to perform well in population-based samples including young and non-daily tobacco users.