Incidence of cardiovascular disease in a historical cohort of Danish firefighters

Abstract

ObjectivesFirefighters are exposed to multiple cardiovascular hazards, but few epidemiological studies have addressed their cardiovascular morbidity. The objective of this study was therefore to examine the incidence of cardiovascular diseases (CVD) in Danish firefighters.MethodsWe used individual historical employment records on 11.691 male Danish firefighters supplied by trade unions and fire agencies. The Supplementary Pension Fund Register was used to establish two occupational reference groups (a random sample from the male employed population and military employees). Information on CVD incidence was retrieved from the nationwide Danish National Patient Registry. SIRs and Poisson regression analyses (incidence rate ratio) were used for estimation of risks, including 95% CIs.ResultsIn comparison with the population sample, the age-adjusted and calendar time-adjusted SIR for all CVDs combined was increased in firefighters (SIR=1.10, 95% CI 1.05 to 1.15). The risk was also elevated for the most frequent outcomes, including angina pectoris (SIR=1.16, 95% CI 1.08 to 1.24), acute myocardial infarction (SIR=1.16, 95% CI 1.06 to 1.26), chronic ischaemic heart disease (SIR=1.15, 95% CI 1.06 to 1.24) and atrial fibrillation/flutter (SIR=1.25, 95% CI 1.14 to 1.36). This analysis showed the most elevated SIRs for CVD in full-time firefighters compared with part-time/volunteer firefighters. Both types of firefighters employed <15 years had an increased risk of CVD. Similar risk patterns appeared in comparisons with the military. Internal analysis supported external findings.ConclusionThe risk of overall CVD, including the most frequent subtypes was modestly increased in Danish firefighters and was most elevated in full-time firefighters compared with other male employees.