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%, p < 0.001). Extremely low atmospheric pressure increased risk by 85% with a threshold effect and no significant linear trend. Higher temperature raised risk by 12% (IRR = 1.12, 95% CI: 0-24%, p < 0.05). Wind speed and daily temperature difference showed no significant associations. During lag days 1-4, effects of humidity and daily temperature difference peaked at lag 1 day. Temperature exerted divergent effects at lag 1 and 2 days. No lag effects were observed for wind speed or atmospheric pressure.

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.