Measuring cigarette dependence: A comparison of two scales in two different groups of smokers

The Fagerström Test for Cigarette Dependence (FTCD) and the Cigarette Dependence Scale (CDS) are usually used to assess cigarette dependence in clinical- and population-based studies. Our objective was to compare these two scales within groups of smokers from both contexts.

The study was observational with smokers from a representative sample of the adult general population (n=188) and smokers attending a smoking cessation clinic in Barcelona, Spain (n=759). The FTCD and the CDS-5 (short version of 5 items) were used to assess cigarette dependence. We compared the standardized median scores obtained with both scales within each group of smokers by selected variables. To this aim, we re-scaled the scores of both scales to allow their comparison and assess their correlation within both groups.

The scores obtained with both scales were highly correlated within both groups of smokers (p<0.001), indicating good agreement in the assessment of cigarette dependence. Nevertheless, higher standardized CDS-5 scores were observed more frequently in the population group overall (3.9 vs FTCD score=3.7, p=0.001), among women (4.5 vs 4.2; p<0.001), in the youngest group of smokers (3.9 vs 3.2; p<0.007) and in light smokers (time to the first cigarette >60 min; 1.7 vs 1.1; p<0.001).

While the CDS-5 scored higher more frequently in the population group, the FTCD scored higher more frequently in the clinical group. These differences should be considered when designing either clinical- or population-based studies.