Quality of deployment surveillance data in southwest Asia

The Global Expeditionary Medical System (GEMS), formerly known as Desert Care II, provides clinical data on every medical encounter that occurs at U.S. Air Force medical treatment facilities in theater. After 22 months of surveillance from March 1997 to January 1999, 59,026 records were generated from 27,305 active duty members. A random sample of 273 individuals were reviewed for four key fields: chief complaint, diagnosis, International Classification of Diseases, 9th Revision, code, and disease and nonbattle injury category. The vast majority (> 99%) of records were consistently classified and reported. An unrelated subset of all cases categorized as "Medical/Other" seen at Prince Sultan Air Base (5,640 records) also were analyzed. Reassignment was made in 19% of cases into other categories, suggesting that further refinement of disease and nonbattle injury reporting is needed for effective deployment medical surveillance. Overall, this electronic data-gathering system has high internal validity, consistency, and reliability for service members in the deployed U.S. Air Force setting.