The Usefulness of Heavy Smoking Index as a Test for Nicotine Dependence

Background: The Fagerstrom Test for Nicotine Dependence (FTND) is a widely used six- item questionnaire. Its completion require a few minutes, but such time may be too much for busy clinicians and large epidemiologic surveys. The goals of this study was to compare the sensitivity and the specificity of Heavy Smoking Index (HSI) of high nicotine dependence. Methods: The FTND was administered to 943 current smokers from a smoking- cessation clinic in Gwangjin-gu, Seoul. The HSI which combines two items of the FTND (the number of cigarettes per day and the time of the first cigarette of the day) was compared to the FTND. We measured cigarette per day, duration of smoking, and age of smoking initiation. Results: A cutoff score equal or greater than 4 on the HSI detected a similar rate of nicotine dependence as a cutoff score equal or greater than 6 on the FTND. The HSI showed a sensitivity of 88.0% and a specificity of 86.5%. The concordance between the two instruments was high (kappa=0.74). Conclusion: The HSI was proven to be very useful. If HSI had a proper validity, the HSI can be a good standard of high nicotine dependence for busy clinician and epidemiologists.