A Brief Measure of High Nicotine Dependence for Busy Clinicians and Large Epidemiological Surveys

Abstract

Objective: It is important to perform a routine screening of nicotine dependence in psychiatric patients. The Fagerström Test for Nicotine Dependence (FTND) is a widely used six-item questionnaire. The Heavy Smoking Index (HSI) is a briefer measure including only two FTND items (time to first cigarette of day and number of daily cigarettes). In a prior study comparing HSI with FTND, a high HSI (score ≥ 4) was a good and briefer alternative for detecting high nicotine dependence. The goals of this study were: (i) to compare the effectiveness of the HSI with the effectiveness of Items 1 and 4 alone for the screening of high nicotine dependence; (ii) to investigate the optimality of 4 as a cut-off score for the HSI so that the HSI can be used as a binary indicator of high nicotine dependence; and (iii) to compare the sensitivity and specificity of four indexes of high nicotine dependence, namely ‘High HSI’, ‘Very Early Smoking’, ‘Heavy Smoking’ and ‘High in Either Item’. Method: The FTND was administered to 819 current daily smokers from a general population survey. As in a prior study, an FTND score ≥ 6 was considered the reference or ‘gold standard’ test for detecting high nicotine dependence. Receiver-operating characteristic analyses were performed. Results: This new study using more sophisticated statistical methodology verified that a cut-off of 4 for the HSI is appropriate and that the ‘high’ HSI has good sensitivity and specificity even across different population subclassifications. Conclusions: With four questions (smoking, daily smoking, time to first cigarette of day and number of daily cigarettes) and minimal calculations, it may be possible to screen whether a smoker has high nicotine dependence. If other studies in other populations and settings verify this finding, this brief measure might be an ideal screening instrument for busy clinicians, epidemiologists developing questionnaires for health surveys and psychiatric researchers. Key words: nicotine dependence, receiver-operating characteristic analyses, sensitivity, specificity, tobacco smoking.