Firefighters and on-duty deaths from coronary heart disease: a case control study

Abstract

Background: Coronary heart disease (CHD) is responsible for 45% of on-duty deaths among United States firefighters. We sought to identify occupational and personal risk factors associated with on-duty CHD death.

Methods: We performed a case-control study, selecting 52 male firefighters whose CHD deaths were investigated by the National Institute for Occupational Safety and Health. We selected two control populations: 51 male firefighters who died of on-duty trauma; and 310 male firefighters examined in 1996/1997, whose vital status and continued professional activity were re-documented in 1998.

Results: The circadian pattern of CHD deaths was associated with emergency response calls: 77% of CHD deaths and 61% of emergency dispatches occurred between noon and midnight. Compared to non-emergency duties, fire suppression (OR = 64.1, 95% CI 7.4-556); training (OR = 7.6, 95% CI 1.8-31.3) and alarm response (OR = 5.6, 95% CI 1.1-28.8) carried significantly higher relative risks of CHD death. Compared to the active firefighters, the CHD victims had a significantly higher prevalence of cardiovascular risk factors in multivariate regression models: age >or= 45 years (OR 6.5, 95% CI 2.6-15.9), current smoking (OR 7.0, 95% CI 2.8-17.4), hypertension (OR 4.7, 95% CI 2.0-11.1), and a prior diagnosis of arterial-occlusive disease (OR 15.6, 95% CI 3.5-68.6).

Conclusions: Our findings strongly support that most on-duty CHD fatalities are work-precipitated and occur in firefighters with underlying CHD. Improved fitness promotion, medical screening and medical management could prevent many of these premature deaths.

Figure 1

Circadian Distribution of Firefighter Fatalities compared with the Distribution of Emergency Calls.

Figure 2

Circadian Distribution of CHD Deaths for Firefighters and the General Population.

Figure 3

Percent of On-duty CHD Fatalities occurring in Firefighters ≤ 50 years old and Relative Risk of CHD Death as a Function of Different Duties. Red Boxes: Horizontal line inside each box corresponds to the OR for CHD death for each activity vs. non-emergency activity. Upper horizontal line corresponds to the upper limit of the 95% CI, and the lower horizontal line corresponds to the lower limit of the 95% CI. Blue Boxes: Horizontal center of each box corresponds to the proportion expressed as a percent of CHD deaths that occurred among firefighters ≤ 50 years old in each activity.