Source: www.jamanetwork.comAuthors: Samir Soneji, PhD; James D. Sargent, MD; Susanne E. Tanski, MD, MPH; Brian A. Primack, MD, PhD Associations Between Initial Water Pipe Tobacco Smoking and Snus Use and Subsequent Cigarette Smoking: Results From a Longitudinal Study of US Adolescents and Young Adults Importance Many adolescents and young adults use alternative tobacco products, such as water pipes and snus, instead of cigarettes. Objective To assess whether prior water pipe tobacco smoking and snus use among never smokers are risk factors for subsequent cigarette smoking. Design, Setting, and Participants We conducted a 2-wave national longitudinal study in the United States among 2541 individuals aged 15 to 23 years old. At baseline (October 25, 2010, through June 11, 2011), we ascertained whether respondents had smoked cigarettes, smoked water pipe tobacco, or used snus. At the 2-year follow-up (October 27, 2012, through March 31, 2013), we determined whether baseline non–cigarette smokers had subsequently tried cigarette smoking, were current (past 30 days) cigarette smokers, or were high-intensity cigarette smokers. We fit multivariable logistic regression models among baseline non–cigarette smokers to assess whether baseline water pipe tobacco smoking and baseline snus use were associated with subsequent cigarette smoking initiation and current cigarette smoking, accounting for established sociodemographic and behavioral risk factors. We fit similarly specified multivariable ordinal logistic regression models to assess whether baseline water pipe tobacco smoking and baseline snus use were associated with high-intensity cigarette smoking at follow-up. Exposures Water pipe tobacco smoking and the use of snus at baseline. Main Outcomes [...]