CVD in Korean firefighters: A retrospective study from 2002 to 2015

Purpose: This study was performed to estimate incident rate of cardiovascular diseases (CVD) in firefighters, and to compare hazard ratios with police officers, public educational officials and national and regional governmental officers in a Korean nationwide sample. Methods: A total of 860,517 (548,503 male and 312,014 female) employees (23,356 firefighters, 92,359 police officers, 338,857 public educational officials, and 405,463 national and regional government officers) were chosen for this study. Data were from the National Health Insurance Service from 2002 to 2015, and age-standardized cause-specific incident rates of firefighters and other occupational groups were estimated by calculating the incidence cases per 100,000 person-years. Cox proportional hazard regression analysis was used to assess hazard ratios (HR) and 95% confidence intervals (95% CI) for CVD between firefighters and other occupational groups. We included four types of CVD (hypertension, angina pectoris, acute myocardial infarction, and cerebrovascular disease) in this study. Results: Age-standardized incident rates for CVD in male firefighters were 2170 for hypertension, 931 for angina pectoris, 192 for acute myocardial infarction, and 601 for cerebrovascular disease, respectively. In female firefighters, age-standardized incident rates were 1265 for hypertension, 454 for angina pectoris, 157 for acute myocardial infarction, and 389 for cerebrovascular disease, respectively. These firefighters’ incident rates of hypertension, angina pectoris, and cerebrovascular disease in male, and those of angina pectoris and cerebrovascular disease in female were lower than those of other three occupational groups. But, age-standardized incident rate of acute myocardial infarction was higher than that of public educational officials and national and regional government officers in male, and that of other three occupational groups in female. In result of Cox proportional hazard regression analyses, compared to national and regional government officers, firefighters were more likely to develop CVD (HR: 2.107, 95% CI: 1.935-2.293 for acute myocardial infarction, HR: 1.304, 95% CI: 1.255-1.354 for angina pectoris, HR: 1.233, 95% CI: 1.176-1.292 for cerebrovascular disease, and HR: 1.234, 95% CI: 1.204-1.265 for hypertension, respectively). Conclusions: This study suggests that firefighters are more likely to increase cardiovascular risks due to shiftwork, frequent emergency calls, work over-load, long working time, and other occupational stress compared to other occupational groups. These results are very surprising in that firefighters’ health conditions are strongly required when they were newly recruited, and in that they seem to be healthier workers than other workers. The health management program and institutional system to reduce job stress in doing their jobs, should be established in individual and organizational levels.