Tags:  E-cigarette, vaping, cannabis, lung injury, legalization

  

The problem: In the US, cannabis is illegal at the federal level due to its classification as a Schedule I substance. However, several US states have liberalized their cannabis laws and 33 US states have legal cannabis policies; 11 of these states permit legal adult use of cannabis for recreational purposes. Since late 2019, several cases of e-cigarette/vaping product use-associated lung injuries were reported in the US. Many patients who suffered these lung injuries reported vaping illegally obtained cannabis-derived oils.

 

The study: The risk of e-cigarette/vaping product use-associated lung injuries may be higher in US states where cannabis use remains illegal, as there is no regulatory oversight in these states. This study explores the relationship between the incidence of e-cigarette/vaping product use-associated lung injuries and state-level cannabis policies.

 

Main results: The authors obtained publicly available information (state health department, press releases) on e-cigarette/vaping product use-associated lung-injuries from all 50 US states between September 2019 and March 2020 (states with medical-only and those with no active retail markets were excluded). The odds of experiencing an e-cigarette/vaping product use-associated lung-injury were calculated according to policy status (active, legal adult-use vs. illegal access).
 

• The authors identified 2,958 confirmed or probable cases of e-cigarette/vaping product use-associated lung-injuries across all 50 US states.

• Cumulative incidence of e-cigarette/vaping product use-associated lung injuries per 100,000 past-month cannabis users in all states with legal cannabis laws vs. those with no legal access to cannabis were 5.19 (95% confidence interval: 4.7–5.7) vs. 15.89 (95% confidence interval: 14.9–17.0).

• The odds of e-cigarette/vaping product use-associated lung injuries were 3.06 (95% confidence interval: 2.7–3.5) times higher in states with illegal access to cannabis, compared to those with legal access.

  • Massachusetts imposed a ban on vaping products during this study period; after excluding this state, these odds were ~4-fold higher in states with illegal vs. legal access.

• Further, after adjusting for state population, significantly fewer cases of e-cigarette/vaping product use-associated lung injuries were observed in states with legal cannabis vs. illegal cannabis use.
   

Conclusions: The study shows ~3-fold higher odds of lung injuries due to vaping/e-cigarettes among cannabis users living in states with no legal access to cannabis, compared with those in states with recreational use policies.

 

Why this is a good study:

• This is good study because the authors utilized data from ~13 million past-month cannabis users in the US and adjustments were made for state population size.

• E-cigarette/vaping product use-associated lung injuries have been attributed to illegally obtained cannabis and vaping additives (e.g. vitamin E acetate). This study offers a new perspective on these lung injuries by examining the roles played by state-level cannabis policies in these events.

 

Why this isn’t a perfect study:

• The study only examined the incidence of lung injuries among cannabis users who used e-cigarettes/vaping products. Any additive effects from alternative forms of cannabis consumption or other substances were not considered.

• Despite legalization of cannabis, many states have illegal cannabis markets. It is likely that lung injuries reported in states with legal cannabis use may have occurred due to illegally obtained cannabis. There were no adjustments to control for this possibility.

 

What this study adds:

• The study shows a protective effect of state-level cannabis policies on the incidence of e-cigarette/vaping product use-associated lung injuries. This may be due to legal access to safer cannabis products that are tested/regulated by the state.

 

What it doesn’t:

• The study did not examine specific policy elements (e.g. safety testing) that may have alleviated these lung injuries.

• Further, the impact of amount of cannabis consumption on the incidence of e-cigarette/vaping product use-associated lung injuries was not measured.

 

Funder: No agency funding was reported.

 

Author conflicts: None.