In 2021, nearly 52.5 million adults in the US reported using cannabis in the past 12-months (Abuse, 2021), including more than 35 % of young adults (18–25 years old) (Abuse, 2021). Cannabis use presents several threats to health and development, including reduced cognitive function (e.g., learning, memory, attention) (Academies and of Sciences E, Medicine, 2017), onset of dependence (i.e., cannabis use disorder) (Montgomery et al., 2022), and possible incarceration due to federal prohibitions that list cannabis as a Schedule I Drug (Mead, 2017). Adding to these risks, nearly 1 in 3 adult users report co-use of cannabis with tobacco cigars (i.e., blunt smoking) (Mantey et al., 2021, Montgomery et al., 2020, Montgomery and Mantey, 2017, Mantey et al., 2022). Blunts, relative to other modalities of cannabis use (e.g., pipes; edibles), expose the user to greater concentrations of carbon monoxide (Cooper and Haney, 2009) and increases the risk for nicotine and cannabis dependence (Schauer et al., 2017, Wadsworth et al., 2022, Russell et al., 2018). Blunts are particularly common among adolescence and emerging adulthood (Kreslake et al., 2023). National data shows 42 % of blunt smoking initiation occurs during late adolescence (ages 14–17) and that nearly half (49.4 %) of all people who smoked blunts are 18–24 years old (i.e., young adults) (Mantey et al., 2021). Given the prevalence and risk profile of blunt smoking, investigation of this form of cannabis and tobacco co-use is critically needed to inform cannabis research (Academies and of Sciences E, Medicine, 2017) and intervention (Administration SAaMHS, 2021).

Prevalence and patterns of blunt smoking differ significantly by race/ethnic category. National studies have found that non-Hispanic Black (NHB) youth (Montgomery and Mantey, 2018) and adults (Mantey et al., 2021, Montgomery et al., 2020, Montgomery and Mantey, 2017, Mantey et al., 2022) are more likely to report lifetime (ever) and past 30-day (current) blunt smoking, relative to non-Hispanic Whites (NHWs) and Hispanics. Further, the majority (63.8 %) of NHB adult cannabis users reported using blunts (Montgomery et al., 2020), compared to 42.9 % of Hispanics and 25.8 % of non-Hispanic White (NHW) adults. Furthermore, approximately 1 in 5 adults (19.3 %) who ever smoked blunts progressed to current use; (Mantey et al., 2022) however, current use was significantly higher among NHB adults (33.8 %), relative to NHW (15.0 %) and Hispanic (21.7 %) adults (Mantey et al., 2022). Unfortunately, the vast majority of research on blunt smoking has relied on cross-sectional data; (Schauer et al., 2017) thus, longitudinal investigation is needed to characterize temporal changes and transitions in blunt smoking among young people, accounting for differences by race/ethnic category.

Along with identifying differences in blunt smoking between racial/ethnic categories, research is needed to understand the shared and discrete risk factors for blunt use initiation, progression, and sustained use across racial/ethnic categories (Alvidrez et al., 2021, Alvidrez et al., 2019). Alcohol use is an example of a shared risk factor for blunt smoking among youth (Montgomery and Mantey, 2018) and young adults (Mantey et al., 2021, Montgomery et al., 2020, Montgomery and Mantey, 2017, Mantey et al., 2022) across racial/ethnic groups (Schlienz and Lee, 2018). Several studies have found a strong association between alcohol and blunt use, especially among young adults and racial and ethnic minorities (Johnson et al., 2006). For example, in an study of cannabis/blunt use in New York City, Dunlap et al (2006) (Dunlap et al., 2006) identified three settings in which blunt smoking often occurred, including “party” settings where alcohol was the main substance consumed and sharing of blunts was strongly encouraged. Moreover, the tobacco industry promotes the relationship between blunt and alcohol use in their development and selling of blunt wraps and little cigars and cigarillos that taste like liquor, such as Courvoisier and strawberry daiquiris (Johnson et al., 2006, Montgomery et al., 2019, Montgomery et al., 2018, Montgomery and Oluwoye, 2016).

Mental health is also an important consideration when attempting to understand and address cannabis use among young people (Leventhal et al., 2020). Research has not established a causal link between cannabis use and poor mental health;(Academies and of Sciences E, Medicine, 2017) however, longitudinal studies have established a temporal relationship between symptoms of depression and increased risk for cannabis use and initiation during adolescence and emerging adulthood (Clendennen et al., 2023, Bataineh et al., 2023, Mantey et al., 2022). Unfortunately, research on mental health and blunt smoking is limited (Academies and of Sciences E, Medicine, 2017) and relies primarily on cross-sectional data (Mantey et al., 2021, Montgomery et al., 2020, Montgomery and Mantey, 2017, Mantey et al., 2022). Similarly, the association between symptoms of poor mental health (e.g., depression) has been linked to increased risk for blunt smoking among NHWs but not among NHB or Hispanics (Montgomery and Mantey, 2017, Montgomery and Mantey, 2018) Our study seeks to expand on the existing research investigating risk factors associated with blunt use across racial/ethnic groups.

This study aims to characterize the longitudinal transitions across lifetime and past 30-day (current) blunt smoking among a diverse cohort of youth and young adults. Transitions were modeled using biannual panel data collected from Spring 2019 to Fall 2021 (baseline + 2.5 years). A three-state Markov model was used to simultaneously estimate these transition intensities across the following states: (1) never blunt smoking; (2) ever but not current blunt smoking; and (3) current blunt smoking. This three-state Markov model estimates transition intensities for four transitional states: (a) from never to ever blunt smoking (i.e., initiation); (b) from never to current blunt smoking (i.e., onset); (c) from ever to current blunt smoking (i.e., continuation); and (d) from current to ever blunt smoking (i.e., discontinuation). The primary objective of this study is to compare transitions in blunt smoking by race/ethnic groups. The secondary aim of this study was to examine predictors of transitions in blunt smoking within and across race/ethnic groups.