Predictors of nicotine dependence among adolescent waterpipe and cigarette smokers: A 6-year longitudinal analysis

Abstract

Objective: Identifying the factors associated with nicotine dependence (ND) is essential to prevent initiation and continued use, and to promote cessation among youth. This study aims to document the predictors of the appearance of initial ND symptoms and full ND syndrome among adolescent waterpipe (WP) and cigarette smokers.

Methods: A 6-year longitudinal study was conducted among 8th and 9th graders from 38 schools in Lebanon. The analysis sample included exclusive-WP (n = 228) and exclusive-cigarette smokers (n = 139). Weighted Cox proportional hazards models were used to characterizing predictors of initial ND symptoms and full ND syndrome.

Results: Predictors of experiencing initial ND symptoms among WP smokers included low maternal educational level, having a sibling who smoked WP, low physical activity, high body mass index (BMI), smoking initiation at a younger age. For cigarette smokers these were being male, younger, having lower BMI, having a sibling who smoked cigarettes, living in a crowded household, and smoking daily. Among WP smokers, predictors of developing full ND syndrome include being younger, believing that WP smokers have more friends, depression, high levels of impulsivity, and initiating smoking at a younger age. For cigarette smokers, predictors of full ND syndrome were being younger and initiating smoking at a younger age.

Conclusion: Smoking cessation and prevention interventions targeting youth should address modifiable, and tobacco use-specific factors that influence the development of ND among young WP and cigarette smokers. They also need to start at a younger age to target those most vulnerable to developing life-long addiction to tobacco products.

Keywords: Adolescent; Cigarette smoking; Nicotine dependence; Waterpipe smoking.

Figure 1.. Study sample flowchart.

In the first model, we excluded those WP (n=116) and cigarette (n=29) smokers who endorsed ND symptoms at the baseline. In the second model, we excluded those WP (n=76) and cigarette (n=29) smokers who had already attained ICD10 criteria at the baseline. Note, the retention rate at wave 8 was 72.3% (i.e., n=179 were lost to follow up at wave 8); among adolescents who were lost to follow up, we excluded those who were either non-smokers or dual users at the time of loss to follow up (n=51). However, adolescents WP (n=79) and cigarette (n=49) smokers who were lost to follow up were included in the analysis (i.e., whether they were diagnosed as dependent or not at the end of the study) to increase the power. E-cigarettes module was added to the WDLY study at wave 8 and current e-cigarette users were excluded from current analysis.