Gulf War Veterans
Limitations of Available Data for Accurately Determining the Incidence of Tumors Gao ID: T-NSIAD-98-186 May 14, 1998None of the data sources providing information on the health of Gulf War veterans can be used to reliably estimate the incidence of tumors or other illnesses. Existing government data systems are generally limited by poor coverage of the Gulf War veteran population and problems of accuracy and completeness. As a result, the number of Gulf War veterans with tumors or whether they have a higher incidence of them than other veterans is unknown. The Departments of Defense (DOD) and Veterans Affairs (VA) have begun efforts to improve these data systems but have not developed the capability to effectively link information from different sources to assess tumors or other illnesses among Gulf War veterans. DOD and VA also recently funded several studies that should provide more information on tumor cases in the future. However, these studies are not the result of a systematic effort to study the incidence of tumors, and limitations to the studies will prevent them from yielding reliable and valid estimates of Gulf War veterans' tumors. A preliminary GAO review of VA's databases identified nearly 15,000 Gulf War veterans with tumors--a larger number of cases than that reported by other studies of Gulf War veterans.
GAO noted that: (1) based on GAO's completed study, none of the data sources providing information on the health of Gulf War veterans can be used to reliably estimate the incidence of tumors or other illnesses; (2) existing government data systems are generally limited by poor coverage of the Gulf War veteran population and problems of accuracy and completeness; (3) as a result, it is not known how many Gulf War veterans have tumors or whether they have a higher incidence of them than other veterans; (4) DOD and VA have begun efforts to improve these data systems but have not developed the capability to effectively link information from different sources to assess tumors or other illnesses among Gulf War veterans; (5) DOD and VA also recently funded a few research studies that should provide additional information on tumor cases in the future; (6) however, these studies are not the product of a systematic effort to study the incidence of tumors, and limitations to the studies will prevent them from providing reliable and valid estimates of Gulf War veterans' tumors; (7) following completion of GAO's report, it conducted additional work to assess the feasibility of linking data from different sources and determining the number of tumors among Gulf War veterans; (8) based on GAO's preliminary analysis of only VA health and disability benefits databases, it identified about 14,700 Gulf War veterans with tumors; (9) although GAO has not conducted appropriate analyses to determine whether the total it computed translates into a higher or lower rate of cases as compared to other groups of veterans, it is a larger number of cases than that reported in other studies of Gulf War veterans; (10) these data reflect cases that are reported in VA data systems and do not include Gulf War veterans who are still on active duty or those who use non-VA medical facilities; and (11) while GAO was able to merge VA data at an aggregate level to estimate the total number of tumors, detailed analysis involving the combination of cases by type of tumor will be more difficult to conduct because of different diagnostic coding systems used in the different data systems.