# Influence of Daily Meteorological Changes on Stroke Incidence Across the United States

## TL;DR

This study finds that daily temperature increases are linked to a small but significant rise in stroke cases across the U.S.

## Contribution

The study identifies a specific and statistically significant relationship between temperature change and stroke incidence.

## Key findings

- A 1°C increase in daily temperature is associated with a 0.47% increase in stroke incidence.
- Other weather variables like pressure and precipitation did not show significant effects on stroke rates.
- The observed effect is small but statistically significant across 92 U.S. healthcare systems.

## Abstract

Various variables of weather are hypothesized to exert a small but measurable, significant influence on the development of cerebral infarctions (strokes). Improved characterization of this relationship would enhance understanding of the impact of climate change on healthcare demand. However, current data are conflicting regarding the exact nature of the direction and magnitude of the relationship between weather variables and stroke incidence.

We conducted a retrospective analysis using patient data from 2019 across the contiguous United States obtained from the TriNetX global research data network and weather data from the National Oceanic and Atmospheric Administration database. Data from hospitalized patients who had a diagnosis of cerebral infarction, as defined from International Classification of Diseases, 10th Rev, diagnosis codes, were used for analysis. Negative binomial regression calculated the incidence rate ratio (IRR) between stroke and various weather variables: temperature (°C), change in temperature, pressure, change in pressure, and precipitation.

Our study included 92,422 patients across 92 healthcare systems. Regression analysis revealed a small but statistically significant association between stroke and change in temperature (IRR 1.0047, confidence interval 1.0012 – 1.0083, P = .010). The remaining variables in our model did not have a statistically significant effect on incidence of stroke.

The data suggest that one aspect of weather, specifically day-to-day increases of ambient temperature, has a measurable small magnitude but statistically significant impact on local stroke patterns.