Our results do not support prior findings of a negative association between marijuana and PPR use. Boehnke, Litinas, and Clauw report that among individuals with chronic pain, use of medical marijuana was negatively associated with opioid use. Further, legalization of medical marijuana has been correlated with a drop in the number of hospitalizations attributed to opioid dependence/abuse and PPR ODs, and a decline in opioid OD mortality rates . States with medical marijuana dispensaries also report fewer PPR ODs, a reduction in PPR treatment admissions, and a decline in opioid-related deaths . However, none of these studies stratified their results by cigarette smoking status. As such, it is possible that the inclusion of only current cigarette smokers in the present study could help explain the discrepancy between the present findings and other results. Of note, studies investigating the effect of marijuana use on opioid/PPR use vary in their sample composition , use of covariates , and outcome measures . This variation in study design is likely responsible for some of the discrepant findings in the extant literature. As previous studies have not stratified their analyses by cigarette smoking status, our study provides an important and unique contribution to current evidence, and this dynamic helps to explain why our findings differ from those that found a negative relationship between marijuana and PPR use. We did not find a significant association between PPR use and frequency of marijuana use among current marijuana users. Our findings align with those of Lucas et al. ,vertical outdoor farming who determined that among Canadian medical marijuana users, there was no association between frequency of marijuana use and illicit drug substitution, though this finding is attenuated because their analysis was not stratified by cigarette use status.
On the other hand, our findings contrast with those of Arterberry et al. , who reported that frequency of marijuana and cigarette use was predictive of opioid use among an adult sample in the NESARC. This dissimilarity may be due to differences in study design. In the work of Arterberry et al. , frequency of marijuana use was determined by asking participants how often they used marijuana in the last year, and responses were coded on a scale from 0 to 10 . In contrast, our participants reported how often they used marijuana within the past month by indicating a specific number of days from 0–30. Second, all participants in our study were current cigarette smokers, while the NESARC sample included both cigarette smokers and non-smokers. There are several study limitations. Though the TABS II used a random sample, it is not nationally representative. All data is self-reported, and there are no biomarkers for verification of tobacco, marijuana, or PPR use. The cross-sectional nature of the analysis prevents causal inference. As there were no non-smokers included in the analysis to compare with the current smokers, further analysis of the present study is warranted. We do not have data on participants’ reason for PPR use. Some participants could have medical provider issued prescriptions for pain, yet it is possible that even patients with valid prescriptions may not actually “need” a prescription pain reliever. We did not have any information on the presence, absence, or type of pain. Studies have shown that simply asking a primary care physician for a narcotic by brand name significantly increases the likelihood of being prescribed a medication and being prescribed a strong narcotic . Because pain is subjective, a definitive conclusion as to what level pain a patient is experiencing is not possible.
Therefore, the only data available in a large data base is whether or not the participant had a prescription for use. We also did not measure the frequency of PPR use within the past 30 days, as we did with marijuana, nor did we ask respondents about the type of PPRs they used. In the future, questions about these details of PPR use would be beneficial to include, as they would enable a more nuanced analysis of the data. Concerning our frequency analysis, it is possible that our sample of current marijuana users was too small to capture a significant effect between frequency of marijuana use and PPR use. Finally, despite random sampling, our sample was predominantly Caucasian and older, limiting generalizability. To frame conclusions about the presence of a complementary effect between marijuana and PPR use and to identify a potential causal relationship between use of these two substances, future studies should be longitudinal, with larger and more diverse samples that include both smokers and non-smokers. The incorporation of unique aspects of MMLs into future models would be useful to more accurately determine the effects of such laws. Rates of adult marijuana use have grown substantially in the US over the past decade, particularly among those aged 26 years or older and those that are daily cigarette smokers . This is of concern, as evidence indicates that marijuana use can lead to addiction and use of other substances, motor vehicle accidents, impaired brain development, psychiatric conditions, and respiratory problems . Concurrent use of tobacco and marijuana is common, although not uniform across tobacco products . Estimates indicate that between 25% and 52% of tobacco smokers use cannabis and, among past month marijuana users, 68% also reported tobacco use . Further, concurrent use of marijuana and tobacco increased from 2003 to 2012 . Use of marijuana and cigarettes or cigars is commonly reported among tobacco users , though less is known about the relationship between marijuana use and multiple tobacco products. About 40% of current tobacco users in the US report use of multiple products, and cigarettes + e-cigarettes are the most common combination .
Among multiple product users, there are also differences in types of products used and prevalence of use by age, gender, and race/ethnic group .The opportunities for co-administration provided by modification of tobacco products may represent one source of interest in tobacco products among marijuana concurrent users . For example, electronic devices engineered to aerosolize tobacco, marijuana, and other substances may be marketed to promote cooccurring use . Tobacco products that can be readily modified for marijuana use may not only increase tobacco use among marijuana users, but also expand the types of tobacco products used by an individual. Frequent use of marijuana has been linked with persistent tobacco use and greater tobacco dependence among youth and adults and higher expectancies that each substance promotes the use of the other . Among concurrent users, motivation to reduce marijuana and the relative perception of harm from use of marijuana have been lower than for tobacco. Concurrent use of marijuana and tobacco products may promote persistent tobacco use and decreased motivation to alter use of marijuana , reduce users’ interest in quitting tobacco , and reduce success in cessation . By impairing cessation efforts, concurrent use may serve to exacerbate the negative consequences from both tobacco and marijuana. The health effects of persistent tobacco use and use of marijuana show clear associations with acute and chronic respiratory symptoms . When combusted, both inhaled tobacco and marijuana smoke deposit tar and other constituents in the lung . Cellular abnormalities associated with respiratory disorders including bronchitis and chronic obstructive pulmonary disease have been observed in both tobacco and marijuana users . A US population examination of respiratory symptoms among marijuana smokers suggested higher rates of bronchitis, coughing, phlegm production, and wheezing after statistically adjusting for cigarette smoking . The effects of marijuana use on respiratory health among other and multiple tobacco product user groups,rolling grow table including users of aerosolized products in the US population, have not been examined. The rapidly changing landscape of tobacco and marijuana products and consumption devices, particularly in the context of marijuana legalization and increasing use, indicate the importance of characterizing patterns of tobacco and marijuana use. Our primary aim is to describe the relationship between current marijuana use and pattern of current tobacco product use using a comprehensive assessment of tobacco products. We hypothesized that users of tobacco would have higher rates of current marijuana use than those not currently using tobacco products and that effects would be strongest for current users of tobacco products with inhaled routes of administration that accommodate co-administration relative to current non-inhaled tobacco product users. We also hypothesized that among current tobacco users, concurrent use of any tobacco product and marijuana would be associated with increased tobacco dependence and a decreased motivation to quit tobacco use. Finally, we hypothesized that concurrent users of inhaled tobacco products and marijuana would have higher rates of respiratory conditions relative to those not currently using tobacco products.We used logistic regression to estimate the relationship between current marijuana use among users and non-users of tobacco products, with non-tobacco-users as the reference group . Planned covariates for all models included age, gender, and racial/ ethnic group. With a focus on current tobacco users, Hypothesis 2 evaluated reports of marijuana use for each user group using cigarette only users as the reference . We then added a term reflecting levels of tobacco dependence and re-evaluated the independent association between tobacco use group and current marijuana use . Logistic regression models were also used to explore relationships between current marijuana use, past quit attempts, and current intentions to quit among current users of tobacco products. Lastly, for Hypothesis 3, logistic regression models were used to estimate the odds of a respiratory condition for current tobacco users relative to those not currently using tobacco. A dummy coded term for current marijuana use was used in interaction terms to assess potential moderating effects of marijuana use on relationships between tobacco product use and respiratory conditions.Among current tobacco users, we first estimated any increase in odds of marijuana use of each user group in reference to cigarette only users .
E-cigarette only, hookah only, and cigarette + e-cigarette users did not differ significantly from cigarette only users in the odds of reporting current marijuana use. Cigar only and multiple product users had significantly greater odds of reporting current marijuana use than cigarette only users.We examined the hypothesis that tobacco dependence may account for significant differences in current marijuana use across tobacco user groups by adding the TD scale to the demographically adjusted model . This hypothesis was not supported, as each significant association noted in Model B remained significant in Model C, and each effect size remained largely unchanged. Level of tobacco dependence was a significant and independent predictor of current marijuana use . Follow-up exploratory analysis did not suggest any moderated relationship between tobacco user groups and TD scores, as the set of interaction terms when added after all other lower-order terms was not significant = 0.53, p = 0.78.The present study examined the differential prevalence of co-use of marijuana among distinct types of tobacco product user groups, impacts on tobacco dependence, efforts to stop tobacco, and current respiratory problems. Cigar only and multiple product users consistently had the highest rates of marijuana use. These product-specific patterns were maintained after adjusting for differences in demographics and after accounting for the strong relationship between tobacco dependence and current marijuana use. Tobacco product characteristics that may afford opportunity for delivery of marijuana may increase their appeal to concurrent users of marijuana. Alternatively, concurrent use may serve to promote expanded use of tobacco products . Rates of concurrent use decreased steadily across age groups for all tobacco product users except smokeless only users, whose rates remained similar to non-users across age groups. While we adjust statistically for the influence of age on the relationship between product use and increased current marijuana use, the increase in concurrent use of these products among youth, where cigar and multiple product use is most common, is of particular concern. However, the extent to which the currently observed greater rates of concurrent use among youth differ from historical patterns is unknown. Differences in product user groups also reflect, in part, differences in tobacco dependence . Associations between concurrent use and dependence are well documented and have plausible mechanisms via enhanced reinforcement, conditioned pairings to strengthen cues for concurrent use, and amelioration of cognitive deficits of marijuana use alone .