As Covid-19 ravages the world and researchers are scrambling to decipher the mystery to controlling its spread, it wasn’t too long ago that another mystery illness caught our attention — electronic cigarette- or vaping-related lung injury (EVALI), which hospitalized more than 2,600 people and caused 68 deaths.
While its numbers pale in comparison to the Covid-19 pandemic, the etiology of EVALI was elusive for some time.
We now know that vaping products that were acquired through informal sources — such as on the street, from friends or family, or through unapproved online sources — and which contained tetrahydrocannabinol (THC) and the additive vitamin E acetate were the factors behind the adverse outcomes. As awareness grew, the cases began to drop.
A new cross-sectional analysis added another level of understanding to the occurrence of EVALI. In states that have legalized recreational marijuana use and THC, EVALI cases are lower than in states where marijuana is illegal or only available for medicinal use.
“This association was not driven by state-level differences in e-cigarette use, and EVALI case rates were not associated with state-level prevalence of e-cigarette use,” Alex Hollingsworth, PhD, from the O’Neill School of Public and environmental Affairs, Indiana University and colleagues wrote in JAMA Network Open. “One possible inference from our results is that the presence of legal markets for marijuana has helped mitigate or may be protective against EVALI.”
The study authors looked at EVALI cases on a state-by-state level (including Washington, DC), obtaining data from the CDC, “estimates of the prevalence of e-cigarette use in each state in 2017 from the Behavioral Risk Factor Surveillance System, and estimates of state populations in 2017 from the Surveillance, Epidemiology, and End Results database.”
They also coded the states as being recreational marijuana states if they had at least one dispensary open by Jan. 1, 2019, and as medical marijuana states if they had a medical marijuana law in effects by Jan. 1, 2019.
They found that recreational states had the lowest occurrence of EVALI.
“The average recreational marijuana state had 1.7 EVALI cases (95% CI, 0.3-3.1) per million population,” Hollingsworth and colleagues wrote. “In contrast, the EVALI case rate was 8.8 cases (95% CI, 5.1-12.5) per million population in medical marijuana states and 8.1 cases (95%CI, 4.1-12.0) per million population in prohibition states. A test of the difference in mean case rates implies that recreational marijuana states have 7.1 (95%CI, −10.9 to −3.2) fewer cases per million than medical marijuana states (P < .001) and 6.4 (95% CI, −10.4 to −2.3) fewer cases per million than prohibition states (P = .004). The difference in the EVALI case rate between medical and prohibition states was not statistically significant (difference = 0.7; 95%CI, −4.5 to 5.9; P = .78).
Interestingly, the study authors noted that there was no association between e-cigarette use and EVALI cases. In other words, more vaping did not necessarily equal more EVALI.
Also, after adjusting for e-cigarette prevalence, they did a multivariable regression to see if there was an association between EVALI cases and marijuana laws, which confirmed their earlier findings.
“The regressions imply that average EVALI case rates were lower in recreational marijuana states by 7.2 (95%CI, −11.8 to −2.6) cases per million population than in prohibition states (P = .003). There was no significant difference between EVALI case rates in prohibition and medical marijuana states (difference = 0.3; 95% CI, −5.3 to 5.8; P = .93). There was no association between the prevalence of e-cigarette use and EVALI case rates (difference = −1.3; 95%CI, −3.3 to 0.7; P = .20).
While the study’s limitations are obvious, particularly its cross-sectional design, it does proffer “interesting questions,” Meghan M. Cirulis, MD, from the Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Utah School of Medicine in Salt Lake City, and colleagues wrote in a commentary accompanying the study.
Particularly, why are there less cases of EVALI where recreational marijuana is legalized?
Cirulis and co-authors noted that the obvious answer is that the legal vaping products are not contaminated with vitamin E acetate, which begs another question — why would this be so?
“One salient possibility is that there is less financial incentive to dilute THC concentrates in states where raw THC material is readily available without legal risk and compensatory markup,” the commentators wrote. “If THC concentrates are transported from states where they are legal and can be relatively cheaply mass produced (like industrial ethanol stocks during Prohibition) to other states where they are illegal and must be guarded jealously as a rare and precious commodity, there may be a strong economic inducement to dilute them, thereby increasing profits. Thus, legalization of marijuana may have protective local effects but untoward collateral effects.”
Nonetheless, Hollingsworth and colleagues’ study raised these and other questions but “points to promising avenues for further research by highlighting the geographic heterogeneity of EVALI suggesting a potential explanation for it,” Cirulis and colleagues wrote. “It also underscores the complex realities of social movements and resulting legislation that may have unforeseen and unforeseeable public health consequences, for better and for worse, that are recognized only in retrospect. If history teaches us anything, it is to be careful.”
A cross-sectional state-by-state analysis of EVALI cases found that there were less cases in states that had legalized recreational marijuana.
Cases of EVALI were higher in states that either had not legalized recreational marijuana or only had legalized medical marijuana.
Candace Hoffmann, Managing Editor, BreakingMED™
Cirulis disclosed no relevant relationships.
Cat ID: 195
Topic ID: 89,195,730,138,143,192,151,195,489,925