Substance Abuse ISSN: 0889-7077 (Print) 1547-0164 (Online) Journal homepage: https://www.tandfonline.com/loi/wsub20 Modes of delivery in concurrent nicotine and cannabis use (“co-use”) among youth: Findings from the International Tobacco Control (ITC) Survey Danielle M. Smith, Connor Miller, Richard J. O’Connor, Lynn T. Kozlowski, Elle Wadsworth, Brian V. Fix, R. Lorraine Collins, Binnian Wei, Maciej L. Goniewicz, Andrew J. Hyland & David Hammond To cite this article: Danielle M. Smith, Connor Miller, Richard J. O’Connor, Lynn T. Kozlowski, Elle Wadsworth, Brian V. Fix, R. Lorraine Collins, Binnian Wei, Maciej L. Goniewicz, Andrew J. Hyland & David Hammond (2020): Modes of delivery in concurrent nicotine and cannabis use (“co-use”) among youth: Findings from the International Tobacco Control (ITC) Survey, Substance Abuse, DOI: 10.1080/08897077.2019.1709603 To link to this article: https://doi.org/10.1080/08897077.2019.1709603 Published online: 17 Jan 2020. Submit your article to this journal Article views: 10 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=wsub20 SUBSTANCE ABUSE https://doi.org/10.1080/08897077.2019.1709603 ORIGINAL RESEARCH Modes of delivery in concurrent nicotine and cannabis use (“co-use”) among youth: Findings from the International Tobacco Control (ITC) Survey Danielle M. Smith, MPHa,b, Connor Miller, MSa, Richard J. O’Connor, PhDa, Lynn T. Kozlowski, PhDb, Elle Wadsworth, MScc , Brian V. Fix, MAa, R. Lorraine Collins, PhDb, Binnian Wei, PhDa, Maciej L. Goniewicz, PhDa, Andrew J. Hyland, PhDa, and David Hammond, PhDc aDepartment of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA; bDepartment of Community Health and Health Behavior, University at Buffalo, Buffalo, New York, USA; cSchool of Public Health and Health Systems, University of Waterloo, Waterloo, Ontario, Canada ABSTRACT KEYWORDS Background: Cannabis use is more common among nicotine users than non-users. This study char- Cannabis; nicotine; youth; acterized concurrent use of nicotine and cannabis (“co-use”) among 12,064 youth aged 16–19 years vaping; co-use; modes residing in Canada, the United States, and England in 2017. Methods: Data were from the ITC of delivery Youth Tobacco & Vaping Survey (Wave 1). Seven modes of cannabis delivery (MOD) were charac- terized by country of residence and past 30-day use of combusted tobacco and electronic ciga- rettes. Weighted multivariable regression models were fitted to assess the correlates of co-use and each cannabis MOD. Results: Seventy percent of cannabis users reported nicotine use. Co-users exhibited behavioral and demographic differences compared to exclusive users of either sub- stance. “Smoking cannabis without tobacco” was the most popular form of use (78%). Use of nico- tine-containing e-cigarettes was associated with “using an e-cigarette to vape cannabis oil/liquid” (aOR: 4.96, 95%CI: 2.23–11.06). Combustible tobacco use was associated with “smoking cannabis with tobacco in a joint/blunt” (aOR: 2.93, 95%CI: 1.89–4.56). Country-level differences were detected. Conclusions: Nicotine use is substantial among cannabis users, and associations exist between modes of delivery for both drugs. Results underscore the importance of studying canna- bis and nicotine use concurrently, and the need to address the use of both substances in develop- ing interventions for youth users. Introduction cannabis use, and 3.9% reporting exclusive nicotine use.8 Prior research suggests there are a number of problems Use of cannabis and nicotine among youth presents a sub- related to co-use, including heavier nicotine and cannabis stantial global public health burden, with an estimated 13.8 use, greater dependence on both substances, difficulty in – million youth aged 15 16 years reporting past-year use of quitting cannabis use, linkage to problematic use of alcohol cannabis in 2016, and 25 million youth reporting current 1 and other illicit drugs, increased likelihood of experiencing use of cigarettes or smokeless tobacco. Youth commonly psychotic symptoms later in life, and elevated exposure risks – experiment with these substances, which may present ele- for smoke-related toxicants.9 13 Commonalities in the pri- vated health harms related to brain development and risks mary route of administration for both substances (i.e., 2,3 of developing substance use disorders. In many high- inhalation) have been posited as reinforcing mechanisms of income countries, rates of youth cigarette smoking are co-use, which may serve to further compound-related health declining, while youth trial and use of electronic cigarettes harms.14 The significant overlap between the modes of deliv- (“e-cigarettes”) and electronic vapor products is increas- ery used to administer cannabis and nicotine may also con- – ing.4 6 In tandem, changes in cannabis policies have contrib- tribute to emerging co-use patterns. Many tobacco products uted to considerable expansion of the cannabis market in can be used for cannabis administration (i.e., flavored rolling recent years, with a greater diversity of products and modes papers, blunts),15,16 and vaporized modes of delivery are of delivery in both “illegal” and “legal” markets.7 available for both substances.17,18 The use of cannabis and nicotine are often studied in iso- Cross-national differences in cannabis and nicotine lation with respect to the other substance. However, concur- modes of delivery exist, yet often remain unexamined rent use (“co-use”) of cannabis and nicotine is common, through the lens of co-use. Smoking remains the predomin- with estimates showing 5.4% of youth reporting co-use in ant form of cannabis delivery, but specific practices related the United States, compared with 2.2% reporting exclusive to cannabis smoking are regionally and culturally CONTACT Danielle M. Smith, MPH [email protected] Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Elm & Carlton Streets, Buffalo, NY 14263, USA. ß 2020 Taylor & Francis Group, LLC 2 D. M. SMITH ET AL. determined.19 For example, mixing cannabis and tobacco in the survey was kept anonymous and used exclusively in “spliffs”/“mulled cigarettes” (i.e., joints that mix tobacco aggregate form during analyses.29 with cannabis) or “blunts” (i.e., cigars that have been hol- lowed out and filled with cannabis) are common co-admin- Measures istration practices, with spliff use being far more common in Western European countries, and blunt use occurring more Cannabis use and modes of delivery 19–21 frequently in North American countries. Further, coun- Cannabis use was assessed using the following question: tries with a different regulatory treatment of e-cigarettes and “When was the last time you used marijuana/cannabis?” vaping products display differences in public perceptions of (response options: “I have never used cannabis;”“Earlier 22 these products, and their subsequent adoption and use. today;”“Not today but sometime in the past week;”“Not in For example, in England, authorities place substantial the past week but sometime in the past month;”“Not in the restrictions on e-cigarette advertising, promotion, and allow- past month but sometime in the past 6 months;”“Not in the able nicotine content in the products, which have been past 6 months but sometime in the past year;”“1 to 4 years largely normalized for the purpose of tobacco smoking ces- ago;”“5 or more years ago”). Participants who responded 23 sation. A recent cross-national study showed that past 30- “earlier today”; “not today but sometime in the past week”; day nicotine vaping was less common among youth in or “not in the past week but sometime in the past month” England compared to youth in the United States and 24 were classified as past 30-day cannabis users. Past 30-day Canada. Cultural contexts specific to nicotine products cannabis users were asked to report on their use of seven could influence cannabis use behaviors and vice versa. different modes of delivery: “In the last 30 days, did you … :” Characterizations of co-use in light of diversifying modes (a) “smoke cannabis without tobacco;” (b) “smoke cannabis of delivery remain sparse,25,26 and have not been examined with tobacco in a joint or blunt;” (c) “use a waterpipe or in a cross-national context. The primary objective of this bong to smoke cannabis;” (d) “use a vaporizer to heat dried study was to characterize cannabis and nicotine co-use pat- cannabis leaves or herb;” (e) “use an e-cigarette to vape can- terns among youth aged 16–19 years in three countries, nabis oil or liquid;” (f) “eat or drink cannabis in a food or based on their past-30 day use of different modes of canna- beverage;” (g) “use cannabis extracts, including oil, wax or bis and nicotine delivery. Secondary objectives aimed to shatter” (response options for each: Yes, No). assess correlates of co-use and specific cannabis modes of delivery. Nicotine use and modes of delivery “ Methods All respondents answered the following questions: Have you ever tried a cigarette, even one or two puffs?”; “Have Data source you ever tried an e-cigarette, even one or two puffs?” Participants who responded “Yes” were successively asked: Data are from Wave 1 of the International Tobacco Control “When was the last time you used a … [cigarette/e-ciga- Policy Evaluation Youth Tobacco and Vaping Survey, con- ” ducted in July/August 2017 among 12,064 youth aged rette]? Youth selected from the following answers: (a) “ ” “ 16–19 years, in Canada (CA; n ¼ 4008), England (EN; Earlier today; (b) Not today but sometime in the past ” “ n ¼ 3970), and the United States (US; n ¼ 4086). Participants 7 days; (c) Not in the past 7 days but sometime in the past ” “ were recruited through Nielsen’s Consumer Insights Global 30 days; (d) Not in the past 30 days but sometime in the ” “ Panel and affiliated partners using a blend of probability past 6 months; (e) Not in the past 6 months but sometime ” “ ” “ and non-probability-based sampling strategies.