Meteorological factors modulate idiopathic epistaxis risk: a 12-year retrospective study in Changshu.

Objective: To investigate the incidence of idiopathic epistaxis in Changshu, China, and its correlations with meteorological factors. Methods: We retrospectively enrolled 24,193 patients with idiopathic epistaxis from March 2011 to November 2022. Matched clinical, population, and meteorological data were analyzed. Spearman's correlation and variance inflation factor analyses were performed to assess multicollinearity. We conducted quartile stratification and sequential robust negative binomial regression with three progressively adjusted models, as well as 1-4 day lag effect analyses. Results: The highest incidence was in patients <18 years (40.3%) and the lowest in those ≥60 years (14.3%), while males accounted for approximately 60% of all cases. Incidence was higher in spring (32%) and summer (27%). Regression analysis showed that higher relative humidity reduced disease risk by 17% (IRR = 0.83, 95% CI: -21 - -12%, Conclusion: Low humidity and high temperature are independent risk factors for idiopathic epistaxis. Atmospheric pressure presents a threshold effect, and meteorological factors exert diverse short-term lag effects on disease onset.