Heaviness of Smoking Index, Number of Cigarettes Smoked and the Fagerstrom Test for Nicotine Dependence Among Adult Male Malaysians

Two methods of identifying smokers with high nicotine dependence, the heaviness of smoking index (HSI) andnumber of cigarettes per day (CPD) were compared with the Fagerstrom test for nicotine dependence (FTND).The HSI, CPD and the FTND were administered to 316 adult Malaysian male, daily smokers aged between25-64 years old in the Malaysian NCD Surveillance-1 Survey using a two-stage stratified random samplingof enumeration blocks and living quarters, via an interview based on a validated questionnaire. The cut-offpoint for classification of high nicotine dependence on the HSI was a score of four or higher, and for the heavysmoking category, smoking more than 20 cigarettes per day. Classification using each method was comparedwith classification by the FTND (score of six or more) as the reference standard. Sensitivity, specificity andkappa statistics for concordance between both measures and the FTND were evaluated. The HSI gave a similarprevalence rate of high nicotine dependence as the FTND. There was substantial agreement between the HSI andthe FTND (kappa=0.63.), with moderate sensitivity (69.8%) and high specificity (92.5%). However, prevalenceof high nicotine dependence using the CPD was 7% lower than the FTND. The heavy smoking category alsoshowed fair agreement with the FTND (kappa=0.45) and moderate sensitivity (67.0%), but specificity was high(86.9%). The findings indicate that the HSI can be used as an alternative to the FTND in screening for highnicotine dependence among daily smokers in large population-based studies, while CPD may not be a suitablealternative to the FTND.