Temperature and Mortality in Nine US Cities

• Published in: Epidemiology (Cambridge, Mass.) Vol. 19; no. 4; pp. 563 - 570
• Main Authors: Zanobetti, Antonella, Schwartz, Joel
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Lippincott Williams & Wilkins 01-07-2008; Lippincott Williams & Wilkins, Inc
• Subjects: Air Pollutants - adverse effects; Air Pollutants - analysis; Air pollution; Biological and medical sciences; Cities; Climate change; Death; ENVIRONMENT; Epidemiology; General aspects; Humans; Medical sciences; Meta-Analysis as Topic; Miscellaneous; Mortality; Mortality - trends; Ozone; Public health. Hygiene; Public health. Hygiene-occupational medicine; Seasons; Temperature; Time series analysis; United States - epidemiology; Urban Population; Weather; United States; North America; America; Human; Urban environment; Atmospheric temperature; Epidemiology; Mortality; Public health
• ISSN: 1044-3983; 1531-5487
• DOI: 10.1097/EDE.0b013e31816d652d

Background: Extreme temperatures have been associated with increased mortality worldwide. The extent to which air pollutants may confound or modify this association remains unclear. Methods: We examined the association between mean apparent temperature and total mortality in 9 cities across the United States during the warm season (May to September) from 1999 to 2002. We applied case-crossover and time-series analyses, adjusting for day of the week and season in time-series analysis. City-specific estimates were then combined using a meta-analysis. A total of 213,438 deaths for all causes occurred in these cities during the study period. Results: We found that mortality increased with apparent temperature. A 5.5°C (10°F) increase in apparent temperature was associated with an increase in mortality of 1.8% (95% confidence interval = 1.09% to 2.5%) when using case-crossover analysis and with an increase of 2.7% (2.0% to 3.5%) using the time-series analysis. Conclusions: This study provides evidence of increased mortality due to elevated apparent temperature exposure, with no confounding or effect modification due to air pollution.