Cannabis Use and Risk of Chronic Rhinosinusitis and Sinus Surgery.

Objective: While cannabis' link to asthma is well-studied, its impact on CRS is less clear. This study explores the association between cannabis use and rates of new-onset chronic rhinosinusitis (CRS), chronic rhinosinusitis with nasal polyps (CRSwNP), and functional endoscopic sinus surgery (FESS) rates. Methods: The TriNetX Analytics Research Network was queried for adults ≥ 18 years old, stratified into cannabis user and non-user cohorts based on electronic health record data from January 2012 to December 2019. Separate cohorts of patients with pre-existing CRS-with and without cannabis use-were analyzed to evaluate associations with FESS. Primary outcomes were relative risks of new-onset CRS and CRSwNP encounter diagnosis and FESS 1, 2, and 5 years after initial cannabis use diagnosis. Results: After 1:1 propensity score matching, cohorts analyzing CRS and CRSwNP included 73,091 patients each. Cannabis use was associated with reduced risk of unspecified CRS at 1 year (aRR = 0.87, 95% CI 0.80-0.95), 2 years (aRR = 0.84, 95% CI 0.78-0.90), and 5 years (aRR = 0.83, 95% CI 0.78-0.87). There was no difference in risk of CRSwNP at any timepoints. For FESS outcomes, matched cohorts included 5591 patients with pre-existing CRS; cannabis users had lower risk at 1 year (aRR = 0.67, 95% CI 0.47-0.96), 2 years (aRR = 0.64, 95% CI 0.46-0.88), and 5 years (aRR = 0.69, 95% CI 0.52-0.91). Conclusions: Patients with cannabis use demonstrated significantly reduced risks in new-onset diagnoses of CRS and FESS compared to non-users. Further studies are warranted to examine the cause of this relationship. Level of Evidence: 4.