A comparison of the content-, construct- and predictive validity of the cigarette dependence scale and the Fagerström test for nicotine dependence.

Abstract

Research showed that the widely used Fagerstrom test for nicotine dependence (FTND) does not cover important aspects of dependence. A new test, the cigarette dependence scale (CDS-12), covers the main elements in DSM-IV and ICD-10 definitions of dependence. We compared the psychometrics of CDS-12, FTND, and CDS-5 and the heaviness of smoking index (HSI), which are short versions of CDS-12 and FTND, respectively. Internet survey in 2002-2003. Participants were invited one month after answering the first survey to answer a second survey on smoking status and withdrawal symptoms. Eight hundred two smokers answered both surveys. Cronbach's alpha coefficients were higher for CDS-12 (0.91) and CDS-5 (0.77) than for FTND (0.68) and HSI (0.63). Among 231 smokers who quit smoking at follow-up, higher baseline CDS-12 scores predicted higher withdrawal ratings at follow-up, for all withdrawal symptoms except appetite. FTND and HSI predicted higher craving in quitters, but did not predict the intensity of other withdrawal symptoms. Neither CDS-5, FTND or HSI predicted smoking cessation, but higher CDS-12 scores marginally predicted smoking cessation at follow-up (area under the receiver operating characteristic (ROC) curve = 0.55, 95% confidence interval = 0.51-0.59). CDS-12 had better content validity and internal consistency than FTND and was a slightly better predictor of withdrawal symptoms. Unexpectedly, higher (not lower) CDS-12 scores predicted subsequent smoking cessation, perhaps because endorsement of some CDS-12 items implies accepting that one is dependent, which in turn could reflect motivation to quit. CDS-12 may represent an alternative to FTND for measuring cigarette dependence.