Abstract W P123: Associations of Temperature and Average Dew Point With Stroke Hospitalizations and Mortality

Abstract

Background: Some studies suggest meteorological factors may affect stroke incidence and mortality, but results are inconsistent. We investigated the effects of average annual temperature, daily temperature fluctuation, and average dew point on ischemic stroke hospitalizations and mortality in a nationally representative sample from the United States. Methods: Ischemic stroke hospitalizations (ICD-9 433, 434, 436) were identified for those ≥18 years of age from the Nationwide Inpatient Sample 2009-2010. Temperature and dew point data were obtained from the National Climatic Data Center and linked to stroke discharges at the county level. Hierarchical logistic regression was used to assess the relationship between meteorological variables and stroke hospitalization and in-hospital mortality, adjusting for region, season, and patient demographics and comorbidities. Results: We identified 134,510 ischemic stroke hospitalizations (mean age 72 ± 14 years). In unadjusted analyses, each 1°F increase in average temperature was associated with a 0.86% decrease in the odds of stroke hospitalization and a 1.1% decrease in the odds of dying in-hospital after stroke. Increases in daily temperature fluctuation and average dew point were associated with an increased odds of stroke hospitalization (ORs 1.02 and 1.01, respectively), but were not associated with in-hospital mortality. These relationships persisted in risk-adjusted analyses (Figure). Conclusions: Larger daily temperature changes and higher average dew point were associated with higher stroke hospitalization, while lower average annual temperatures were associated with both hospitalization and mortality after stroke. Further research is needed to understand these effects to develop prevention strategies for vulnerable populations during periods of extreme weather conditions.