Cannabinoid Hyperemesis Syndrome ER Visits Surged During COVID and Stayed High

CHS-proxy visits increased from 4.4 per 100,000 ED visits in 2016 to a peak of 33.1 in Q2 2020, remaining elevated at 22.3 in 2022. Concurrently, CVS-only visits declined from 300 to 186 per 100,000. Highest risk: ages 18-25 (RRR 3.59) and 26-35 (RRR 2.26). Females had slightly lower risk (RRR 0.92). Southern US had lower risk vs. Northeast (RRR 0.46).

Cross-sectional analysis of the Nationwide Emergency Department Sample (~85% of annual US ED visits), 2010-2022. 188.6 million unweighted visits (806 million weighted). CHS proxied by co-occurrence of cannabis-related condition and cyclic vomiting syndrome. Restricted cubic splines and multinomial logistic regression.

CHS is increasingly recognized but still frequently misdiagnosed as cyclic vomiting syndrome. The sharp rise during COVID may reflect increased cannabis consumption during lockdowns, and the sustained elevation suggests this is not a temporary phenomenon.

The decline in CVS diagnoses as CHS rises suggests improved recognition of CHS — many previously diagnosed CVS cases may actually have been CHS. The COVID surge and sustained elevation indicate that CHS will become an increasingly common ED presentation.

CHS identified by proxy (cannabis diagnosis + CVS diagnosis), which may over- or underestimate true prevalence. ICD coding changes during study period. Cannot determine if COVID-era increase was from more cannabis use or more ED visits for vomiting.