A latent class analysis of patterns of tobacco and cannabis use in Australia and their health-related correlates.

INTRODUCTION: The shifting landscape in Australia's tobacco and cannabis policies and emerging new products and modes of administration may increase experimentation and the risks of addiction to these drugs. METHODS: We analysed cross-sectional data from the 2019 National Drug Strategy and Household Survey (n = 22,015) of Australians aged 14 and above. Latent class analysis was used to identify distinct groups based on types of tobacco and cannabis products used. The socio-demographic, health-rated correlates and past-year substance use of each latent class was examined. RESULTS: A four-class solution was identified: co-use of tobacco and cannabis (2.4%), cannabis-only (5.5%), tobacco-only (8.0%) and non-user (84.0%). Males (odds ratio [OR] range 1.5-2.9), younger age (OR range 2.4-8.4), moderate to high psychological distress (OR range 1.3-3.0), using illicit substances in the last year (OR range 1.41-22.87) and high risk of alcohol use disorder (OR range 2.0-21.7) were more likely to be in the tobacco/cannabis use classes than non-users. Within the co-use class, 78.4% mixed tobacco with cannabis and 89.4% had used alcohol with cannabis at least once. DISCUSSION AND CONCLUSIONS: Approximately 16% of respondents used tobacco or cannabis, or both substances, and no major distinct subgroups were identified by the use of different product types. Mental health issues and the poly-substance use were more common in the class who were co-users of cannabis and tobacco. Existing policies need to minimise cannabis and tobacco-related harms to reduce the societal burden associated with both substances.

Trends and Socio-Demographic Differences of Cannabis Vaping in the USA and Canada.

Given the rise in cannabis vaping, it is important to highlight the heterogeneity in vaping different cannabis product because of the potential differences in their health risks. This study aims to estimate the trends and socio-demographic correlates of the use of various cannabis vaping products across jurisdiction with different legal status. Data from the 2018 (n = 27,169) and 2019 (n = 47,747) waves of the International Cannabis Policy Study (ICPS) were used. Respondents aged 16-65 completed web-based surveys. In 2019, proportions of past year vaping of cannabis oil, dried flower and concentrates in the overall sample were highest in U.S. jurisdictions where cannabis was legalized for non-medical use (17.4%, 6.0%, 4.9%), followed by U.S. jurisdiction where non-medical cannabis use is illegal (13.7%, 5.8%, 2.9%), and lowest in Canada (8.1%, 4.4%, 2.1%). Vaping dried flower decreased from 2019 to 2018 in U.S. legal jurisdictions and Canada, while vaping cannabis oil and concentrates increased in all jurisdictions (p < 0.001). The odds of vaping all forms of products were higher among younger respondents (16-55 years), males, respondents with some college education, and persons with low-risk perceptions on daily cannabis vaping. In both ICPS surveys (2018 and 2019), cannabis oil was the most frequently vaped products, followed by dried flower, and concentrates. Detailed measures of product forms for cannabis vaping should be considered in future surveys.

Prevalence of Adolescent Cannabis Vaping: A Systematic Review and Meta-analysis of US and Canadian Studies.

Importance: Vaping products were initially designed to deliver nicotine as a tobacco cigarette substitute (eg, electronic cigarettes) but are now frequently used to deliver psychoactive substances, such as cannabis and its derivatives. Large, nationally representative surveys, such as Monitoring the Future, found that approximately 1 in 3 grade-12 students vaped cannabis in 2018 alone. Objective: To summarize the findings of epidemiological studies that reported the global prevalence of cannabis vaping in adolescents by survey year and school grades. Data Sources: PubMed, PsycINFO, Scopus, and Web of Science were searched systematically on August 19, 2020, for studies published globally between January 1, 2003, and August 19, 2020. Study Selection: Publications that reported the prevalence of cannabis vaping in adolescents in the general population were included. Data Extraction and Synthesis: Study characteristics and prevalence estimates were extracted from each article. Random-effects meta-analysis based on the DerSimonian and Laird method and meta-regression were performed on lifetime, 12-month, and 30-day prevalence estimates. Meta-regression was also conducted using survey year and school grades as moderators. Main Outcomes and Measures: Prevalence of cannabis vaping. Results: Seventeen studies met the eligibility criteria (n = 198 845 adolescents). Although no restrictions were imposed on study location, all 17 studies were from the US and Canada. Across all school grades, the pooled prevalence increased for lifetime use (6.1% in 2013-2016 to 13.6% in 2019-2020), use in the past 12 months (7.2% in 2017-2018 to 13.2% in 2019-2020), and use in the past 30 days (1.6% in 2013-2016 to 8.4% in 2019-2020). Heterogeneity across studies was large. The limited evidence from studies using similar survey and study designs suggested that adolescents' preference for cannabis products other than dried herbs, which usually contain higher Δ9-tetrahydrocannabinol levels, may have shifted over time. Conclusions and Relevance: The findings of this study suggest that the prevalence of cannabis vaping has increased among adolescents in the US and Canada and that more effective preventive and response measures are required. Trial Registration: PROSPERO Identifier: CRD42020219644.