Extreme Temperatures and Mortality: Assessing Effect Modification by Personal Characteristics and Specific Cause of Death in a Multi-City Case-Only Analysis

Environ Health Perspect. 2006 Sep;114(9):1331-6. doi: 10.1289/ehp.9074.

Abstract

Background: Extremes of temperature are associated with short-term increases in daily mortality.

Objectives: We set out to identify subpopulations and mortality causes with increased susceptibility to temperature extremes.

Methods: We conducted a case-only analysis using daily mortality and hourly weather data from 50 U.S. cities for the period 1989-2000, covering a total of 7,789,655 deaths. We used distributions of daily minimum and maximum temperature in each city to define extremely hot days (>/= 99 th percentile) and extremely cold days (</= 1st percentile) , respectively. For each (hypothesized) effect modifier, a city-specific logistic regression model was fitted and an overall estimate calculated in a subsequent meta-analysis.

Results: Older subjects [odds ratio (OR) = 1.020 ; 95% confidence interval (CI) , 1.005-1.034], diabetics (OR = 1.035 ; 95% CI, 1.010-1.062) , blacks (OR = 1.037 ; 95% CI, 1.016-1.059) , and those dying outside a hospital (OR = 1.066 ; 95% CI, 1.036-1.098) were more susceptible to extreme heat, with some differences observed between those dying from a cardiovascular disease and other decedents. Cardiovascular deaths (OR = 1.053 ; 95% CI, 1.036-1.070) , and especially cardiac arrest deaths (OR = 1.137 ; 95% CI, 1.051-1.230) , showed a greater relative increase on extremely cold days, whereas the increase in heat-related mortality was marginally higher for those with coexisting atrial fibrillation (OR = 1.059 ; 95% CI, 0.996-1.125) .

Conclusions: In this study we identified several subpopulations and mortality causes particularly susceptible to temperature extremes. This knowledge may contribute to establishing health programs that would better protect the vulnerable.

Publication types

  • Case Reports
  • Historical Article
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Child, Preschool
  • Cities / epidemiology
  • Demography
  • Educational Status*
  • Environmental Exposure / adverse effects*
  • Environmental Exposure / history
  • Environmental Exposure / statistics & numerical data
  • Health Status*
  • History, 20th Century
  • Hot Temperature / adverse effects*
  • Humans
  • Infant
  • Infant, Newborn
  • Life Style*
  • Middle Aged
  • Mortality / trends*
  • Risk Factors
  • United States