Accurately classifying cannabis blunt use as tobacco-cannabis co-use versus exclusive cannabis use.

BACKGROUND: Historically, blunt use constituted tobacco-cannabis co-use based on the products available for creating blunts (e.g., hollowed-out cigars filled with cannabis). With the introduction of tobacco-free blunt wraps (e.g., hemp wraps), blunt use now may constitute tobacco-cannabis co-use or exclusive cannabis use. We examined adolescents' use of tobacco and tobacco-free blunt products and highlighted how misclassification of tobacco-cannabis co-use versus exclusive cannabis use may occur if products used to make blunts are not assessed. METHODS: 4855 students from eight Connecticut high schools completed an online survey in 2022. Use of tobacco products for making blunts (e.g., cigarillos, tobacco blunt wraps) and tobacco-free blunt wraps were assessed as was the use of other tobacco products (e.g., e-cigarettes, cigarettes, hookah). The analytic sample comprised 475 students who endorsed lifetime blunt use. RESULTS: Tobacco-free blunt wraps (72.6%) were the most popular product for making blunts, followed by cigarillos (56.5%), tobacco blunt wraps (49.2%), and large cigars (13.0%). When classified into mutually exclusive groups, students reported exclusive tobacco-free blunt use (32.3%), exclusive tobacco product blunt use (27.4%), or use of both tobacco product and tobacco-free blunts (40.3%). Among those exclusively using tobacco-free blunts, 13.4% endorsed no tobacco product use. CONCLUSIONS: Tobacco-free blunt wraps were very popular among high school adolescents, highlighting the importance of assessing products used for making blunts. Assuming that blunts contain tobacco without considering tobacco-free blunts can lead to misclassification of blunt use as tobacco-cannabis co-use when it actually reflects exclusive cannabis use, potentially leading to inflated estimates of tobacco use. DATA AVAILABILITY: Data will be made available upon reasonable request to the corresponding author.