It was also legal in Australia, but narrow qualifying medical conditions meant that very few people were able to access it. In mid- 2018, recreational cannabis was nationally illegal in all four countries. However, in the US, 8 states and DC had legalized cannabis for recreational use; Canada was in the process of implementing the Cannabis Act to legalize recreational cannabis ; and some Australian states had decriminalized possession in small quantities . The main aim of this descriptive study was to examine cannabis use by cigarette smokers in countries with relatively more permissive cannabis policies versus less permissive policies based on laws that were in place at the time of the survey. For example, laws were more permissive in North America with regard to wide medical access in Canada and the US, as well as recreational cannabis legalization in some US states. With regard to tobacco smoking, all four countries had similar cigarette smoking rates . National tobacco control policies were stronger in Canada, Australia, and England compared to the US, where tobacco control laws varied widely between states. This study also examined cross-country differences among co-users: frequency of cannabis use and of cigarette smoking, relative harm perceptions of smoked cannabis compared to cigarettes, and frequency of smoking cannabis mixed with tobacco among those who reported smoking cannabis.Weighting survey data is one of the major components in survey sampling, and involves attaching a weight to each unit of the selected sample in order to obtain estimates of population parameters of interest. This process essentially incorporates a method of re-balancing the data, in order to more accurately reflect the population. This is especially important for complex survey designs . In the current study, cross-sectional weights were computed for all respondents. A raking algorithm was used to calibrate the weights on smoking status, geographic region, and demographic measures . Finally, the weights were rescaled to sum to the sample size for each country to allow for cross-country comparisons.
This study found significant cross-country differences in patterns of cannabis co-use among cigarette smokers, where smokers from Canada and the US had higher rates of co-use, daily cannabis use, dual-daily co-use of cannabis and cigarettes, were more likely to smoke cannabis without tobacco,vertical grow systems for sale and believe that smoked cannabis is less harmful than cigarettes than co-users in England and Australia. These findings, obtained during a period of liberalization in many countries, introduce a number of important issues for future research on the impact of cannabis liberalization in general, and on tobacco-cannabis co-use. Currently there is mixed evidence about the effects of cannabis legislation on actual changes in cannabis use, and the majority of the available studies originate from the US . Reviews have shown that cannabis use may increase among adults in locations that have legalized medical or recreational cannabis, and a recent large cross-sectional study that examined the population-level impact of recreational cannabis legalization in Canada and across US states in 2018, found that both the prevalence and frequency of cannabis use were higher in US states that have legalized recreational cannabis compared to Canada and US ‘illegal’ states . Recent national data from Canada and the US have shown that adult cannabis use has been increasing where liberalization of cannabis laws has occurred. Some research has also shown that the prevalence of co-use is rising in the US , with higher co-use rates in US states where medical cannabis has been legalized . It is currently unclear however if higher rates of cannabis use, co-use, and/or increases in use are attributable to policy changes, or if studies are detecting pre-existing trends that were in motion prior to liberalization, partly owing to the sophisticated illicit markets in Canada and the US. Moreover, while some studies have examined how cannabis use and co-use patterns may change during the period immediately following a policy change , very little is known about how cannabis liberalization may impact longer-term patterns of tobacco and cannabis co-use. One public health implication to cannabis liberalization is the possibility that increased access to cannabis may weaken, or even reverse, longstanding downward trends in tobacco use. Ongoing, long-term research utilizing longitudinal study designs is critical to further explore the relationship between co-use and liberalization of medical and recreational cannabis. With growing public support and social acceptibility of cannabis in many countries , coupled with cannabis policy liberalization, harm perceptions of cannabis may be impacted. For example, some studies have shown that perceptions of absolute cannabis risks are lower, or have decreased, in jurisdictions that have legalized cannabis , and lower harm perceptions are associated with use and appeal of drugs , including cannabis .
Not much is known about how product regulations may shape or change absolute perceptions about cannabis, and to our knowledge, there are no studies that have compared perceptions of relative risk between smoked cannabis and tobacco, particularily among co-users residing in different cannabis policy environments. A study by Popova et al. found that yong adults in Colorado perceive combustion-smoking as more harmful than non-combustible products , but there was nocomparison between cigarettes and smoked cannabis . A qualitative study of young adults has suggested that co-users in Maryland relate to their use of both substances in different ways, and may underestimate the harms of tobacco use in relation to their cannabis use, as well as underestimate the harms of cannabis use . There is no evidence however if the underestimation of these risks varies between legal and illegal cannabis jusisdictions, as well as between single product users and co-users. While our study cannot determine this, our data do show that co-user’s perceptions of lower relative risk of cannabis compared to cigarettes was substantially more common in Canada and the US. This is worrisome because tobacco smoke and cannabis smoke have been found to contain many of the same carcinogenic chemicals , and some of these harmful constituents have been found in marijuana smoke at greater concentrations than in tobacco smoke . However, regardless of the harmful constituents within each product, tobacco smoking is more deadly and addictive than cannabis. Tobacco smoking is attributed to 8 million global deaths each year, and the total annual global economic cost of smoking is estimated to be 1.4 trillion USD . Currently, there is much less evidence about the health effects of cannabis due to its status as a prohibited substance in most jurisdictions. Studies have shown that regular cannabis use is related to important adverse health outcomes including impaired decision making and memory deficits, increased risks of acute injuries, including impaired driving, dose-dependent risk of developing psychotic disorders, and high health care costs . However the scope and magnitude of these risks are substantially less than tobacco, which is a primary risk factor for a wide range of diseases including several non-communicable diseases, and more than a dozen forms of cancer . This study has demonstrated that the majority of co-users, regardless of the cannabis regulatory environment, are smoking cannabis alongside smoking cigarettes. One main difference was that fewer cousers from Canada and the US mixed tobacco with their cannabis compared to co-users in England and Australia.
Research has consistently shown that co-use practices differ by country and region , which our findings also support. Simultaneous use is more common in European countries and Australia, while sequential use is more common in North America . However, in the US specifically, smoking ‘blunts’ is a common and increasing method of cannabis use . Because tobacco is not directly mixed with cannabis, users may not consider this to be simultaneous use , therefore this use pattern could have been underestimated by US co-users in this study. Research suggests that simultaneous use is associated with greater risk of problematic cannabis dependence, negative cannabisrelated outcomes, lower motivation to reduce tobacco consumption, and lower rates of smoking cessation . On the other hand, it has been found that sequential users use cannabis on more days per month, more cannabis per day, and found that not mixing tobacco with their cannabis to be more pleasurable in comparison to those who mix tobacco with their cannabis . Monitoring unique patterns of both simultaneous and sequential co-use occurring in different regions warrants significant public health attention. Notably however, regardless of couse patterns, nearly one-third of the sample in this study smoked cigarettes and used cannabis daily. While this study is not representative of cannabis-dependent people, there are several smokers who are at much higher risk of the additive effects of co-use. Physicians and other healthcare professionals should be vigilant in identifying co-users and offer tailored treatment, especially for co-users with cannabis dependence, as these users are significantly less likely to quit smoking and problematic cannabis use than those without cannabis dependency . Although this is a large study with representative smokers from four countries, there are some limitations to consider. First, comparing different policy environments is challenging, owing to the diversification of cannabis supply, possession, and use laws, both across and within countries, poor comparisons between national surveys, illicit cannabis markets, and because changing laws are in very early stages . Future research is needed that tackles the difficult challenge of incorporating information about illicit cannabis into analyses of the legal market. Second, the countries included herein were treated as single jurisdictions , which has the potential to mask important sub-national differences. Third, this is a cross-sectional study, therefore temporality issues exist, and causality cannot be determined. Fourth, the sample was limited to adult smokers, so observations may not apply to other populations of interest. Fifth, Canada had not yet officially legalized recreational cannabis at the time of data collection; therefore users would have purchased cannabis illegally or from a legal medical source . Sixth, cannabis use may be underestimated due to respondents’ reluctance to admit to cannabis use. Finally, four high-income Western countries were included in the analyses presented in this paper; therefore, these results may not apply to other countries.Severe acute respiratory syndrome coronavirus 2 has caused >9.4 million infections and >232,000 deaths in the US as of November 4th, 2020. State governments have enforced social distancing, quarantine, and shelter-in-place policies, thereby sequestering communities and limiting access to medical care.
Although critical for protecting public health, such policies have psychological consequences, including fear, anxiety, depression, and post-traumatic stress symptoms. Further, inability to access healthcare may exacerbate chronic disease symptoms. People using cannabis medically represent one potentially vulnerable population, as many use cannabis for chronic conditions such as chronic pain, cancer, and multiple sclerosis. Although cannabis remains Schedule I under the Controlled Substances Act, use of cannabis medically has increased nationwide – even in states without legal cannabis. Of thirty-three states allowing medical cannabis, mobile grow systems only twenty-three have designated cannabis businesses as essential, allowing them to stay open during shelter-in-place orders. This disruption in cannabis access may potentially cause negative health effects for people using cannabis medically through anxiety about cannabis access, symptom flares, and changes in substance use to compensate for the lack of cannabis. For example, some people intentionally substitute cannabis for other medications due to better symptom management and a favorable side effect profile, so some may re-initiate or increase use of other medications due to decreased cannabis access. Alternately, studies show that individuals using medical cannabis report greater use/misuse of prescription drugs and alcohol than those who do not. This population may thus be at particular risk of increasing substance use to cope with COVID-19-related stressors and lockdown/quarantine policies. We sought to understand how people using cannabis medically are affected by COVID-19, with specific focus on cannabis access and use of other medications and substances . We hypothesized that concern about/decreased access to cannabis would be associated with increased use of medications and substances.Participants were from 44 states and Washington, DC, with the highest proportions from California , Pennsylvania , Florida , and New York . Ninety-two percent reported current shelter-in-place policies. Consistent with a nationally representative sample of people using medical cannabis, approximately one-third of participants rated their emotional and physical health as poor/fair, one-third good, and one-third very good/excellent . Most participants used cannabis both medically and recreationally, a proportion similar to that reported among people using cannabis medically vs. medically and recreationally in nationally representative data.