Disease-related mortality among 21,609 Norwegian male military peacekeepers deployed to Lebanon between 1978 and 1998.

PURPOSE: Our study assessed disease-related mortality among Norwegian male military peacekeepers deployed to Lebanon during 1978-1998.

METHODS: A total of 21,609 peacekeepers were followed from start of deployment through 2013. Standardized mortality ratios (SMRs) were calculated based on national rates for the overall cohort, by length of time since first deployment to Lebanon, and for service during high- and low-conflict periods. Poisson regression was used to determine the effect of conflict exposure.

RESULTS: In the overall cohort, a decreased risk was seen for all-cause mortality (1213 deaths, SMR = 0.85), mortality from neoplasms (SMR = 0.89), and from non-neoplastic diseases (SMR = 0.68). Disease-related mortality was lower during the first 5 years of follow-up, while mortality from external causes was elevated. After 5 years, mortality from neoplasms and external causes were similar to national rates, but mortality from non-neoplastic diseases remained lower. The high-conflict exposure group had a two-fold increased risk of mortality from non-neoplastic diseases (rate ratio = 2.33), including ischemic heart disease (rate ratio = 2.25) compared to the low-conflict exposure group.

CONCLUSIONS: We found a "healthy soldier effect" for all-cause mortality and disease-related mortality, but for neoplasms, this effect disappeared after 5 years. Conflict exposure was positively correlated with increased risk of mortality from non-neoplastic diseases.