Association of vaping-related lung injuries with rates of e-cigarette and cannabis use across US states.

BACKGROUND AND AIMS: Responses to the 2019 US outbreak of 'e-cigarette or vaping product use-associated lung injury' (EVALI) ranged from temporary restrictions on nicotine e-cigarette sales to critiques of state cannabis policies. However, if either mass-marketed nicotine e-cigarettes or cannabis use per se drove this outbreak, as opposed to an additive in regionally available black-market e-liquids, states' rates of vaping and/or cannabis use should predict their EVALI prevalence. This study tests that relationship.

DESIGN

Observational study of EVALI data from US states' health departments

SETTING

United States.

PARTICIPANTS

All US states (n = 50).

MEASUREMENTS: The outcome of interest was each state's total EVALI cases per 12-64-year-old resident-an age group covering most EVALI patients-as reported in the second week of January 2020. Predictors are 2017-18 rates of adult e-cigarette use and past-month cannabis use by state.

FINDINGS: The average state EVALI prevalence was 1.4 cases per 100 000 12-64-year-olds. Maps suggest a high-prevalence cluster comprising seven contiguous states in the northern Midwest. EVALI cases per capita were negatively associated with rates of vaping and past-month cannabis use, with the preferred specification's coefficients at -0.239 [95% confidence interval (CI) = -0.441, -0.037; P = 0.02] and -0.086 (95% CI = -0.141, -0.031; P = 0.003), respectively. Robustness checks supported this finding.

CONCLUSIONS

In the United States, states with higher rates of e-cigarette and cannabis use prior to the 2019 'e-cigarette or vaping product use-associated lung injury' (EVALI) outbreak had lower EVALI prevalence. These results suggest that EVALI cases did not arise from e-cigarette or cannabis use per se, but rather from locally distributed e-liquids or additives most prevalent in the affected areas.