Background: The purpose of this research was to compare Heaviness of Smoking Index (HSI), high early
smoking, and heavy smoking with the Fagerstrom Test for Nicotine Dependence (FTND) and further to
evaluate the sensitivity of HSI, high early smoking, and heavy smoking among existing smokers.
Methods: A cross sectional study was conducted by using FTND questionnaire among 200 existing smokers. The
cut-off point for HSI was kept at 4; high early smokers and heavy smokers were classified as those individuals
who smoked within 30 minutes after waking up and individuals who smoked 30 cigarettes or more daily,
respectively. Receiver-operating characteristic (ROC) analysis and Cohen's Kappa statistics were evaluated.
Findings: A significant agreement was observed between the HSI and the FTND, having Kappa value of 0.70,
with good sensitivity of 78.16% and specificity as high as 91.15%. The ROC analysis confirmed that a cut-off
score of 4 for HSI was suitable. Agreement between FTND and high early smoking was observed to be moderate
(Kappa = 0.47, P < 0.001), while very low agreement (Kappa = 0.19, P < 0.001) was observed for FTND and
Conclusion: Results show that HSI is an effective tool which can be substituted for the conventional FTND by
the clinicians, psychotherapists, and investigators in health research.