A Group-Based Modeling Approach to Identify Developmental Trajectories of Nicotine Dependence Among Lebanese Adolescents Waterpipe Smokers.

<bold>Introduction: </bold>Adolescence represents a critical period in which nicotine dependence (ND) symptoms are developing. Little is known about waterpipe (WP) smoking and developmental trajectories of ND criteria across adolescence.<bold>Aims and Methods: </bold>Here, we aimed to identify ND trajectories from early- to late-adolescence in current (past 30 days) WP smokers and examine baseline correlates of each identified trajectory, using the International Classification of Diseases, 10th Revision (ICD-10). The analytical sample consisted of 278 current WP smokers from eight waves of an ongoing longitudinal cohort of eighth to ninth graders in Lebanon. Group-based trajectory modeling was estimated to identify trajectory classes for ICD-10-ND criteria over ages 11-18.<bold>Results: </bold>A group-based modeling approach yielded a four-class solution that best fit the data and reflected differences in the timing of ND onset during adolescence: no-onset of ND (43.9%), early-onset (16.2%), mid-onset (26.6%), and late-onset (13.3%) of ND criteria. Having a less-educated mother (adjusted odds ratio [aOR] = 4.08, 95% confidence interval [95% CI] = 1.01% to 16.53%) and siblings who smoke WP (aOR = 3.95, 95% CI = 1.08% to 14.42%), exposure to favorite WP-specific advertisements (aOR = 3.33, 95% CI = 1.03% to 10.85%), and being a novelty seeker (aOR = 1.12, 95% CI = 1.02% to 1.23%) were associated with early-onset of ND. Daily (aOR = 3.48, 95% CI = 1.08% to 11.23%) or weekly (aOR = 2.20, 95% CI = 1.05% to 4.62%) WP smokers (vs. monthly) and having higher stress level (aOR = 1.07, 95% CI = 1.00% to 1.14%) were associated with mid-onset trajectory. Believing that WP smoking is not harmful to health (aOR = 0.11, 95% CI = 0.02% to 0.82%) and spending less than 60 minutes on a WP smoking session (aOR = 5.62, 95% CI = 1.20% to 26.44%) were associated with late-onset ND trajectory class.<bold>Conclusions: </bold>Monitoring the development of ND trajectories among WP smokers may identify an individual as belonging to one of these four groups with distinct individual and socioenvironmental factors and allow the individual and health care providers opportunities to inform initiate on-time WP-specific tailored prevention and cessation interventions.<bold>Implications: </bold>The results from this study showed a four-class trajectory of ICD-10-ND criteria and suggested that every ND trajectory class during adolescence could have distinctive characteristics and therefore provides new insights into the process of ND in terms of when and what specific interventions are needed to curb the development of ND and long-term WP smoking among youth. [ABSTRACT FROM AUTHOR]