# Correlation Between Meteorological Factors and the Incidence of Emergency Operations: A Retrospective Observational Study at 24 Hospitals in Japan

## TL;DR

This study found that weather factors like atmospheric pressure and humidity are linked to the number of emergency surgeries, which could help predict surgical needs.

## Contribution

The study is the first to explore the relationship between meteorological factors and emergency operations, revealing novel correlations.

## Key findings

- Higher daily mean atmospheric pressure was associated with an increased number of emergency operations.
- An increase in humidity compared to the previous day correlated with more emergency surgeries for subarachnoid hemorrhage.

## Abstract

Background

Although meteorological changes can affect the incidence of the onset of certain diseases, no study has investigated the correlation between meteorological factors and emergency operations. This study aimed to examine a possible association between meteorological factors and the need for anesthetic care for emergency surgery. We hypothesized that changes in atmospheric pressure, temperature, and humidity would be associated with the daily volume of emergency surgeries.

Methods

This retrospective multicenter observational study of emergency operations performed between 2009 and 2017 at 24 Japanese hospitals included a total of 2,423 emergency operations. Meteorological data, including daily mean values of atmospheric pressure, temperature, and humidity, were obtained from the Japan Meteorological Agency. Statistical analysis was performed using univariate and multivariate ordinal logistic regression to elucidate the correlation between the incidence of emergency operations and meteorological factors.

Results

The most common types of operations were gastrointestinal surgery (n = 1161; 47.9%), followed by neurosurgery (n = 496; 20.5%), and obstetrics and gynecology procedures (n = 419; 17.3%). Multivariate ordinal logistic regression analysis revealed a correlation between daily mean atmospheric pressure (OR: 1.0131, 95% CI: 1.0009-1.0255, P = 0.0352) and the number of emergency operations, with the number of emergency operations increasing as daily mean atmospheric pressure increased. Further, multivariate ordinal logistic analysis showed that an increase in mean humidity compared to the previous day was associated with an increase in the number of emergency operations for subarachnoid hemorrhage (OR: 1.1944, 95% CI: 1.0228-1.3966, P = 0.0252).

Conclusion

These results suggest that meteorological factors might enable anesthesiologists to predict the kinds of emergency surgeries likely to be scheduled. However, the mechanisms underlying these findings need to be clarified.