Latent class analysis of initial nicotine dependence among adult waterpipe smokers

Waterpipe (WP) tobacco smoking increases the risk of smoking-related health problems. In this study, we sought to identify the unobserved class memberships of WP-associated initial nicotine dependence (ND) symptoms and assess the predictors of each latent class. This cross-sectional study was conducted among a convenience sample of 900 current (past 30-day) WP smokers who were recruited from 94 WP-serving venues surrounding Tehran and Ardebil metropolitans in Iran. All participants completed a self-administrated questionnaire. We performed latent class analysis using PROC LCA in SAS to identify class memberships of initial ND symptoms using 10-item Hooked on Nicotine Checklist. Five latent classes were identified as non-dependent (25.4 %), low dependent (7.1 %), low-moderate dependent (19.6 %), moderate dependent (15.6 %), and high dependent (32.2 %). Using flavored WP tobacco significantly increased the odds of belonging to low-moderate dependent class [adjusted OR (aOR) = 1.89; 95 % confidence interval (CI): 1.07-3.34] compared to non-dependent class. Also, having academic education decreased the odds of belonging to low-moderate dependent (aOR = 0.43; 95 %CI: 0.26-0.67) and moderate dependent (aOR = 0.39; 95 %CI: 0.23-0.67) class in comparison to non-dependent class. Also, WP smoking initiation at an older age was associated with belonging to high dependent (OR = 2.05; 95 %CI: 1.39-3.03) class compared to non-dependent. This study revealed that nearly half of WP smokers fell under moderate and high-dependent classes. Our findings showed that some items of HONC had more role in the clustering of participants based on ND symptoms. The WP-specific cessation programs and targeted clinical trials should consider the diversity of ND levels among smokers to achieve successful quit rates among these smokers. Additionally, limiting flavors would be a strong strategy to limit the rate of ND, especially among young people who are eager to smoke flavored WP tobacco.