Cannabis use among CVS hospitalizations was linked to shorter stays and fewer readmissions, possibly due to CHS misclassification | Research

The takeaway

In a nationwide analysis of over 35,000 cyclical vomiting syndrome hospitalizations, cannabis use was associated with shorter hospital stays and 37% lower 30-day readmissions, likely because some cases were actually cannabinoid hyperemesis that improved with cessation.

Emergency physicians, gastroenterologists, and medical coding specialists

37% lower readmission risk with cannabis use (likely CHS misclassification)

What the researchers found

Among 35,055 CVS admissions (NIS), cannabis use was associated with reduced length of stay (adjusted mean difference -0.53 days) and 37% lower 30-day readmissions (aHR 0.63). The authors suggest this paradoxical finding likely reflects cannabinoid hyperemesis syndrome (CHS) cases miscoded as CVS, where cannabis cessation during hospitalization improved outcomes.

Why it matters

The overlap between CVS and CHS is a significant diagnostic challenge. This study highlights how ICD coding limitations obscure the true relationship between cannabis and cyclic vomiting.

The numbers in context

35,055 NIS admissions; 31,240 NRD admissions; 6.4% readmitted within 30 days; cannabis use: LOS reduced by 0.53 days (95% CI -0.68 to -0.38); 30-day readmission aHR 0.63 (95% CI 0.54-0.73)

How the study worked

Retrospective nationwide analysis using weighted data from the National Inpatient Sample (NIS, 35,055 admissions) and National Readmission Database (NRD, 31,240 admissions). Multivariate regression assessed predictors of length of stay and 30-day readmission among patients with primary CVS diagnosis.

What this study cannot tell us

Administrative data cannot distinguish CVS from CHS; cannabis use identification depends on ICD coding which may be incomplete; cannot determine if patients ceased cannabis during hospitalization; no data on cannabis use patterns or amounts

How to read the evidence

Large nationwide administrative database study with appropriate regression modeling, but fundamentally limited by inability to distinguish CVS from CHS.

When this study was published

2024 study

The bigger picture

The lack of a specific ICD-10 code for CHS means an unknown number of CHS cases are coded as CVS, confounding research on both conditions and potentially leading to inappropriate treatment approaches.

Questions still open

How many CVS hospitalizations are actually CHS? Would implementing specific CHS ICD codes improve diagnostic accuracy and treatment? What proportion of the reduced readmissions is attributable to cannabis cessation?

Common questions

Why would cannabis use improve CVS outcomes?

It probably does not. The authors suggest many of these "CVS" cases were actually cannabinoid hyperemesis syndrome (CHS), which improves when patients stop using cannabis. Hospitalization often involves temporary cannabis cessation, which would explain the shorter stays and fewer readmissions.

Why are CVS and CHS confused?

There is no specific ICD-10 code for CHS, so these cases get coded as CVS. Both conditions involve cyclic vomiting, making clinical differentiation difficult. The study authors call for specific CHS coding to improve differentiation between these conditions.

Read the original research

Cannabis use and cyclical vomiting syndrome: An open debate.

Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver, 56(2), 272-280

View on PubMed ↗Publisher’s paper ↗

Citation

Kilani, Yassine; Aljabiri, Yazan; Arshad, Iqra; Alsakarneh, Saqr; Aldiabat, Mohammad; Castro Puello, Priscila; Vahanyan, Anush; Vikash, Fnu; Kumar, Vikash; Numan, Laith; Thor, Savanna. (2024). Cannabis use and cyclical vomiting syndrome: An open debate.. Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver, 56(2), 272-280. https://doi.org/10.1016/j.dld.2023.10.002