Long-term mortality amongst Gulf War Veterans: is there a relationship with experiences during deployment and subsequent morbidity?

Background Gulf War Veterans have previously been shown to have, in the short-term, an excess risk of death from 'external' (i.e. non-disease) causes of death. This study aims to determine whether there remains an excess of non-disease-related deaths in Gulf Veterans, 13 years after deployment, and, for the first time, to determine whether there is a relationship between experiences reported in the Gulf, post-war symptoms, and subsequent mortality experience.

Methods We conducted a cohort study with follow-up from April 1, 1991 (the end of the Gulf War) to June 30, 2004. Participants were 53 462 Gulf War Veterans and a cohort of military personnel, matched for age-group, sex, rank, service and level of fitness, who were not deployed to the Gulf. The outcome measure used was mortality as recorded on the NHS central register.

Results There is no difference, 13 years after the end of the Gulf War, in the overall mortality experience of Gulf War Veterans. The excess in non-disease-related deaths previously reported is confined to the initial 7 years of follow-up [mortality rate ratio (MRR) 1.31, 95% confidence interval (CI) 1.06-1.63] rather than the more recent period (MRR 1.05, 95% CI 0.83-1.33). Overall experiences reported during Gulf deployment did not influence subsequent risk of dying, but there was non-significant increased risk of dying from a disease-related death (MRR 1.99, 95% CI 0.98-4.04) associated with reported exposure to depleted uranium and of a non-disease-related death associated with reporting handling of pesticides (MRR 2.05, 95% CI 0.91-4.61). Reporting of morbidity in the health surveys conducted was not related to future risk of death.

Conclusion The higher rates of non-disease-related deaths in Gulf War Veterans is not evident in the period of follow-up since 1997. Neither the excess morbidity reported in health surveys nor the experiences during deployment significantly influenced future mortality. The two non-significant associations found (reported depleted uranium exposure and disease death, reporting handling pesticides and non-disease deaths) need to be considered in the context of the number of possible associations examined and potential biases-although they are biologically plausible.