Mortality and cancer rates amongst Canadian Gulf War veterans mirror those of their military colleagues who did not serve in that conflict, states a major study released by the Department of National Defence. In fact, the rates are slightly better than those for the general Canadian population.
“We found information that we hope is reassuring to Gulf War veterans,” says Dr. Maureen Carew, an epidemiologist with the Canadian Forces Medical Group who participated in the Canadian Gulf War Veterans Cohort Study. An Advisory Committee assembled as part of the study included representatives from the Gulf War Veterans Association, Veterans Affairs Canada, the DND Ombudsman’s office of the Department of National Defence, Statistics Canada and DND.
Conducted by the Gulf War Illness Advisory Committee and Statistics Canada, this research defined a group — or cohort, in statistical parlance — of 5,117 individuals who were posted to active stations in the Persian Gulf between Aug 24, 1990 and Oct 1, 1991. By examining the national database for all deaths in Canada, along with the national cancer registry, the researchers were able to study the occurrence of deaths and cancer within this group between 1991 and 1999.
These figures were then compared with mortality and cancer incidence rates over the same period for a control group of 6,093 military personnel who did not go to the Persian Gulf but were eligible to deploy.
There were no statistically significant differences between the two military cohorts, either in the overall risk of death or the risk of being diagnosed with cancer. Nor did members of either group have a statistically significant different risk of being diagnosed with cancer, when compared with the general population.
However, they did have a statistically significant 50% lower risk of dying than members of the general population, a result that did not surprise Carew.
“We expected that finding,” she says, “because we know that military populations are generally healthier than the Canadian population, because they’re pre-selected before they join, screened out for diseases. They have to maintain higher medical fitness standards during their career.”
This Canadian study parallels the approach of similar research that has already been conducted by military authorities in Australia, the UK, and the US on their respective Gulf War veterans. The Australian study’s statistical interpretation was less reliable because it dealt with fewer than 2,000 veterans, but its results did point to no increase in their risk of dying or being diagnosed with cancer.
The US and UK studies both dealt with much larger groups of veterans, and their statistical findings were more detailed. While the risk of dying overall or from a particular disease was not increased in these studies, closer analysis revealed Gulf War veterans had an elevated risk of dying from external causes — mainly from motor vehicle accidents — in the first few years after the war.
All of these studies follow publicly voiced complaints insisting that the health of many Gulf War veterans was compromised by their experiences in that region. Those complaints have regularly pointed to specific factors, such as the use of anti-chemical weapons measures, reactions to immunization, and possible exposure to low-level chemical or biological agents.
A 1997 Canadian survey addressed these concerns, through a self-completed questionnaire that was mailed to Gulf War veterans and members of a control group. Responses from 3,112 veterans and 3,429 controls revealed that the former had a higher prevalence of self-reported health problems, including joint and bone ailments, as well as skin problems and diseases related to the digestive and respiratory systems.
This same survey also pointed to greater prevalence of symptoms related to chronic fatigue, cognitive dysfunction, depression, anxiety, fibromyalgia, and Post Traumatic Stress Disorder. Similar self-reported illnesses emerged from surveys of US and UK Gulf War veterans, as well as from earlier examinations of veterans of both World Wars and the Vietnam War.
The US study of Gulf War veterans addressed a cohort of over 600,000 veterans, as well as comparable-sized control group. The UK study cohort consisted of more than 53,000 veterans.
Although the Canadian study yielded similar results, the somewhat smaller size of the cohort leads Carew to look forward to a follow-up study that will strengthen its findings.
“We would like to repeat the linkage in the future,” she says, “because we want to continue looking at long-term health outcomes. The longer we wait, the more events will accumulate as the cohort ages, and our statistical power will increase.”
She adds that the Gulf War Veterans Cohort Study has provided a good grounding in the methods and approach for a more general omnibus study, which would apply to the entire Canadian Forces. “We’re in the midst of writing a proposal to do a very similar study but linking our entire forces, so we can monitor the health of CF members when they’re released and during their time in service and monitor outcomes over time,” she says. “It’ll give us a better picture of the health of CF members during their career.”