Seasonality and Coronary Heart Disease Deaths in United States Firefighters

Details

• Personal Author:
  Kales SN ; Mbanu I ; Mittleman MA ; Peeples L ; Stallings LA ; Wellenius GA
• Description:
  United States firefighters have a high on-duty fatality rate and coronary heart disease is the leading cause. Seasonality affects the incidence of cardiovascular events in the general population, but its effects on firefighters are unknown. We statistically examined the seasonal and annual variation of all on-duty coronary heart disease deaths among US firefighters between 1994 and 2004 using the chi-square distribution and Poisson regression model of the monthly fatality counts. We also examined the effect of ambient temperature (apparent as well as wind chill temperature) on coronary heart disease fatalities during the study span using a time-stratified, case-crossover study design. When grouped by season, we observed the distribution of the 449 coronary heart disease fatalities to show a relative peak in winter (32%) and relative nadir in spring (21%). This pattern was significantly different (p=0.005) from the expected distribution under the null hypothesis where season has no effect. The pattern persisted in additional analyses, stratifying the deaths by the type of duty in which the firefighters were engaged at the time of their deaths. In the Poisson regression model of the monthly fatality counts, the overall goodness-of-fit between the actual and predicted case counts was excellent ( X2/4 = 16.63; p = 0.002). Two distinct peaks were detected, one in January-February and the other in August-September. Overall, temperature was not associated with increased risk of on-duty death. After allowing for different effects of temperature in mild/hot versus cold periods, a 1 degree C increase was not protective in cold weather, nor did it increase the risk of death in warmer weather. The findings of this study reveal statistical evidence for excess coronary heart disease deaths among firefighters during winter; however, the temporal pattern coronary heart disease deaths was not linked to temperature variation. We also found the seasonal pattern to be independent of duty-related risks. [Description provided by NIOSH]
• Subjects:
  Cardiovascular Diseases Cardiovascular System Firefighters Morbidity Mortality Occupational Health Safety Temperature
• Keywords:
  Author Keywords: Coronary Heart Disease Cardiovascular System Disease Cardiovascular System Disorders Chronobiology Fatalities Fire Fighters Heart Disease Models Morbidity Rates Mortality Rates Seasonal Factors Seasonality Statistical Analysis Temperature Effects

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• ISSN:
  0742-0528
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Massachusetts ; OSHA Region 1
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  24
• Issue:
  4
• NIOSHTIC Number:
  nn:20057764
• Citation:
  Chronobiol Int 2007 Aug; 24(4):715-726
• Contact Point Address:
  Stefanos N. Kales, MD, MPH, Employee Health & Industrial Medicine, Cambridge Health Alliance, Macht Building, Room 427, 1493 Cambridge Street, Cambridge, MA 02139
• Email:
  gro.ecnaillahc@selaks
• Federal Fiscal Year:
  2007
• Performing Organization:
  Harvard School of Public Health
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Chronobiology International
• End Date:
  20280630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:998852a1a8671e9eee9de76723a20e388ac0ee29e7d5dbf46b9aa1a39c9d18e34132a5b7dfcde5e9986206a43455d30e5fcd6480f74329593be866fff0a7b886
• Download URL:
  https://stacks.cdc.gov/view/cdc/214998/cdc_214998_DS1.pdf
• File Type:
  [PDF - 326.84 KB ]