A number of studies have examined hospitalization rates for blood disorders in deployed and nondeployed veterans. Overall, these studies do not provide evidence that the incidence of blood disorders was different in deployed veterans compared with nondeployed veterans. However, limitations of these studies preclude drawing firm conclusions: hospitalizations were mostly restricted to DoD hospitals, studies did not include information on outpatient visits where patients with mild disorders are most likely to be seen, most studies lacked information on potential confounders, and none of these studies differentiated between potential hematologic disorders. Two additional studies measured hematologic parameters in deployed and nondeployed veterans. Taken together, these two reports did not show any major difference according to deployment status. They were limited, however, by differential participation rate and lack of adjustment for confounding variables. Additionally, some blood disorders typically have a long latency, and hospitalization and mortality studies have limited validity to detect their prevalence and incidence.
The committee concludes that there is inadequate/insufficient evidence to determine whether an association exists between deployment to the Gulf War and disorders of the blood and blood-forming organs.