Unknown population‐level harms of cannabis and tobacco co‐use: if you don't measure it, you can't manage it

Abstract

Background Nationally representative data of cannabis-tobacco co-use have shown that these substances are closely entwined and have significant adverse health consequences, although population-level harms of co-use are largely unknown. Current epidemiological research does not assess co-use in a manner that has yielded the necessary data to draw conclusions regarding health effects. This has given rise to a hidden population of co-users who go under-served. Therefore, this paper has two aims: (1) to review new challenges in the collection of co-use data due to rapidly changing regulations of cannabis and nicotine products and (2) to provide recommendations for the terminology and assessment of couse. Argument We argue that: (1) the prevalence of co-use is not being assessed accurately at a population level and (2) changes in legalization have created novel challenges, but without proper monitoring the impact on co-use will go undetected. We propose a three-level tiered set of recommendations for co-use assessments, which includes assessments of cannabis, tobacco and co-use metrics ranging from least burdensome (self-report of co-administered products) to most burdensome (assays, event-level data). Conclusions We propose that clinical studies begin to incorporate cannabistobacco co-use assessments to justify better their inclusion in clinical trials and national surveillance surveys. Integration of co-use assessments will aid in understanding the true impact on co-use of the changing cannabis and tobacco/nicotine regulatory environments. Co-use is prevalent and problematic, and the ability to make conclusions about its health outcomes is hindered by lack of nuance in data collection. If you do not measure it, you cannot manage it.

Assessing cannabis and tobacco co‐use: the pros and cons of additional data collection

“…From another perspective we must also consider how services addressing cannabis use, which may include primary care, substance misuse services as well as digital treatment options, may address tobacco use. As highlighted by McClure & Hindocha [1], without comprehensive co-use measurement such services may miss the opportunity to assess and treat tobacco dependence, which may also impact upon treatment outcomes for cannabis use. This hidden population of tobacco users who do not identify as 'smokers' is increasingly recognized in the literature [6].…”

“…As McClure & Hindocha [1] highlight, clients in smoking cessation services should be routinely asked about cannabis use, as those accessing services to address cannabis use should be asked about tobacco use, and…”

“…So, while more accurate measurement of substance use is an admirable cause, does the combination of substances smoked make a significant difference to health outcomes? The answer to this question is not fully understood, which is why Hindocha & McClure [1] call for accurate recording of these data and suggest a range of standard measures to be included in research. However, including an additional range of measures on a somewhat sensitive and stigmatized topic in research and clinical practice can be difficult and adds considerable burden to participants/patients.…”

Co‐use measurement is also required in treatment interventions

“…McClure & Hindocha [1] make the argument for improved measurement of tobacco and cannabis co-use in both clinical studies and population level surveys, proposing a tiered system of questions for the research field. In this commentary we expand upon how clinical treatment interventions and services may approach co-use measurement.…”

“…From another perspective we must also consider how services addressing cannabis use, which may include primary care, substance misuse services as well as digital treatment options, may address tobacco use. As highlighted by McClure & Hindocha [1], without comprehensive co-use measurement such services may miss the opportunity to assess and treat tobacco dependence, which may also impact upon treatment outcomes for cannabis use. This hidden population of tobacco users who do not identify as 'smokers' is increasingly recognized in the literature [6].…”