Smoking Dependence, Time-Discounting, and Sustained Cessation Behavior: A Longitudinal Study of Predominantly Light Smokers.

Introduction: This study aimed to assess whether two established psychosocial predictors of smoking abstinence, nicotine dependence and time-discounting, also apply to a population of predominantly cigarette light smokers, which is the dominant pattern of smoking in countries like Mexico. Relatively infrequent smoking is increasingly prevalent, yet still harmful, making it important to understand the predictors of cessation in this population.

Aims And Methods: Mexican adult smokers recruited from an online consumer panel were surveyed every 4 months between November 2018 and July 2020. We considered respondents who reported a quit attempt in between surveys (n = 1288). Dependence was measured with a 10-item version of the Wisconsin Inventory of Smoking Dependence Motives (WISDM). Time-discounting was assessed with five branching questions about hypothetical reward scenarios. Logistic models regressed sustained quit attempts (≥30 days of abstinence) at time t + 1 on study variables at time t.

Results: We found strong interitem reliability (α = 0.92) and intraindividual consistency of our brief WISDM (ρ = 0.68), but moderate intraindividual consistency of the time-discounting measure (ρ = 0.48). Forty-eight percent of the sample reported sustained quit attempts, and 79% were non-daily or light daily smokers (≤5 cigarettes per day). Smokers with higher WISDM-10 had lower odds of sustained quitting and this result remained when controlling for smoking frequency and the Heaviness of Smoking Index (adjusted odds ratio [AOR] = 0.768). Time-discounting was unassociated with sustained quitting.

Conclusions: Our findings suggest that a brief, 10-item multidimensional measure of dependence is useful for predicting sustained quitting in a context of relatively light smoking; time-discounting appears less relevant, although our results are not conclusive because of the low test-retest reliability of our measure.

Implications: Given the increase in non-daily and light daily cigarette smoking in many countries, including in Mexico, and the health risks this still poses, it is important to understand the predictors of cessation among relatively light smokers. The WISDM-10 multidimensional measure seems to be a good instrument to assess dependence and predict successful quitting in this population, and possibly more appropriate than physical dependence measures. As such, it could help design and target more suitable cessation treatments for non-daily and daily light cigarette smokers. While this study did not find time-discounting to be a relevant predictor of smoking abstinence, future studies should explore other measures.