Association Between Adolescent Blunt Use and the Uptake of Cigars.

Importance: Almost two-thirds of adolescents who smoke blunts also report using cigars. Although adolescent co-use of blunts and cigars is prevalent, whether adolescent blunt use is associated with progression to current cigar use (past 30-day use) and increased frequency of use is unknown. Objective: To determine whether adolescent use of blunts is associated with progression to cigar use (past 30-day use) and increased number of days used (in the past 30 days) across the subsequent 24 months compared with adolescents who have never used blunts. Design, Setting, and Participants: In this prospective cohort study of adolescents from 4 public high schools outside of Philadelphia, Pennsylvania, in-classroom surveys were administered at baseline (fall 2016, beginning of 9th grade) and at 6-month intervals for the following 24 months (fall 2018, beginning of 11th grade). Data analyses were conducted in September and October 2019. Exposures: Self-report of lifetime (ever) blunt use at baseline (age 14 years). Main Outcomes and Measures: Progression to current cigar use (use in the past 30 days) and escalation in the frequency of use (number of days used in the past 30 days) across the subsequent 24 months. Results: Of 1825 participants, 907 (49.7%) were female, 1330 (72.9%) were white, and 376 (20.6%) were Hispanic; the mean (SD) age at baseline was 14.38 (0.55) years. In all, 257 participants (14.0%) reported ever blunt use. Mixed-effects models revealed that ever blunt use at baseline vs never blunt use was associated with progression to current cigar use (past 30 days use: odds ratio, 22.66; 95% CI, 11.34-45.27) but not escalation in the number of days used across the following 24 months (β = 0.13; 95% CI, -0.17 to 0.43). Conclusions and Relevance: These findings highlight the risk that blunt use may pose for subsequent cigar use among adolescents. Policies and public health campaigns addressing marijuana as well as cigars will be important to reduce adolescent blunt use and cigar use.