Longitudinal Trajectories of Multiple Nicotine Product Use Among Youths in the Population Assessment of Tobacco and Health Study.

Importance: Multiple nicotine product use (MNPU) among youths is a significant public health concern. Much remains unknown about the patterns of MNPU in youths, including how socioecological factors influence trajectories of MNPU, which may inform targeted prevention. Objective: To identify longitudinal trajectories of MNPU and characterize them according to socioecological factors associated with tobacco use. Design, Setting, and Participants: This US-based longitudinal survey study used data from waves 1 (September 12, 2013, to December 14, 2014) through 4 (December 1, 2016, to January 3, 2018) of the Population Assessment of Tobacco and Health (PATH) study. Participants included 10 086 youths (aged 12-17 years) at wave 1, with follow-up data at waves 2 to 4 (assessed approximately 1 year apart) in the youth or adult data sets. Data were analyzed from January 15, 2020, to December 22, 2021. Exposures: Socioecological factors at wave 1. Main Outcomes and Measures: Outcome variables were days of use in the past 30 days of 4 products: cigarettes, e-cigarettes, cigars, and smokeless tobacco. Factors associated with use of the nicotine products that were collected at wave 1 included sociodemographic factors, internalizing and externalizing symptoms, living with a tobacco user, rules about tobacco use at home, conversations with parents about not using tobacco, tobacco accessibility, and exposure to advertising. Multitrajectory latent class growth analysis was used to identify distinct subgroups with similar patterns of use over time. Multinomial logistic regression models were used to investigate factors associated with class membership. Weights were applied to all data except frequencies to account for the complex survey design. Results: Of the 10 086 youths included in the analysis, 5142 (51.2%) self-identified as male; 4792 (54.7%) were non-Hispanic White; and 5315 (50.6%) were aged 12 to 14 years. Six latent trajectory classes were identified: nonuse (8056 [78.2%]), experimentation (908 [9.8%]), increasing e-cigarette/cigarette use (359 [4.0%]), increasing cigarette/cigar use (320 [3.3%]), decreasing cigarette/e-cigarette/cigar use (302 [3.2%]), and stable smokeless tobacco/cigarette use (141 [1.6%]). Compared with the nonuse class, being older (odds ratio [OR] range, 2.54 [95% CI, 1.94-3.32] to 9.49 [95% CI, 6.03-14.93]), being female (OR range, 0.06 [95% CI, 0.03-0.14] to 0.71 [95% CI, 0.53-0.94]), living with a tobacco user (OR range, 1.43 [95% CI, 1.11-1.83] to 4.94 [95% CI, 3.43-7.13]), and having relaxed rules about noncombustible tobacco product use at home (OR range, 1.41 [95% CI, 1.02-1.94] to 3.42 [95% CI, 1.74-6.75]) were associated with classification in all the use classes. A high degree of difficulty accessing tobacco was associated with lower odds of membership in the increasing cigarette/cigar use vs nonuse classes (OR, 0.62 [95% CI, 0.40-0.98]). Conclusions and Relevance: These survey results highlight the heterogeneity of longitudinal pathways of MNPU in US youths and suggest directions for future prevention and regulatory efforts directed at tobacco use behaviors in this population.