Tobacco Dependence among intermittent smokers

Intermittent smokers (ITS) are an increasingly prevalent segment of smokers, yet it is unknown whether or how dependence severity may vary across ITS. Here we sought to test whether ITS would be less dependent than daily smokers (DS) on multiple dependence measures, and whether variations in dependence among ITS was associated with behaviors such as smoking rate and longest duration of abstinence. 217 ITS (who smoked 4-27 days per month) and 197 DS (who reported smoking every day) were recruited for a study on smoking patterns. Among the ITS smokers, 70 were never daily ITS (NITS) and 138 were converted ITS (CITS; ITS who reported previously being DS); 9 were unknown. Participants completed questionnaires on dependence (time to first cigarette after waking, Fagerstrom Test of Nicotine Dependence [FTND], Nicotine Dependence Syndrome Scale [NDSS], Wisconsin Inventory of Smoking Dependence Motives [WISDM], and Hooked on Nicotine Checklist [HONC]). As we wanted to also evaluate whether the variability in assessed dependence was meaningfully related to smoking behaviors, participants also recorded each cigarette smoked in real time over 3 weeks using Ecological Momentary Assessment. Logistic regression assessed differences in dependence between groups (DS vs. ITS; CITS vs. NITS), and least squares regression examined associations between dependence and smoking behavior (mean, max cigarettes per day; proportion of days smoked; longest period of abstinence) within ITS. As expected, DS were significantly more dependent than ITS: FTND, NDSS & WISDM discriminated between ITS and DS with > 90% accuracy. Similarly, among ITS, NITS demonstrated lower dependence than CITS. Within ITS, dependence measures correlated with observed mean and maximum smoking rates and duration of abstinence, even after accounting for NITS-CITS differences. The study demonstrated that some ITS exhibit features of dependence, suggesting that some aspects of dependence may appear with very infrequent smoking. Future work should examine implications for ITS’ potential progression to daily smoking and cessation outcome.