Hospitalization studies

Gray et al., 1996 (Update)

Retrospective cohort, hospitalizations from August 1991 through September 1993

547,076 active-duty GWVs, 618,335 NDVs

Hospital-discharge diagnoses of circulatory system disease in DoD hospital system (ICD9 classification)

No increase in any-cause hospitalization among deployed GWVs

Prewar hospitalization, sex, age, race, service branch, marital status, rank, length of service, salary, occupation

Very short follow-up period; no outpatient data; restriction to DoD hospitals, and thus to persons remaining on active duty after the war; no adjustment for potential confounders such as smoking

Knoke et al., 1998 (Update)


552,111 deployed vs 1,479,751 nondeployed servicemembers in service during Gulf War and remaining there through 1996

Hospitalization records: DoD only, 1991-1996, ICD 799.9 (unexplained illness)

No excess in hospitalizations in this period when effect of CCEP was eliminated

Race, rank, salary, military branch, occupation, prewar hospitalization, sex

Active duty only, no assessment of outpatient treatment, respiratory findings removed after adjustment for VA screening-program attendance

Gray et al., 2000 (Update)

Retrospective cohort, hospitalizations from August 1991 through December 1994

652,979 GWVs, 652,922 randomly selected NDVs: 182,164 DoD hospitalizations; 16,030 VA hospitalizations; 5185 COSHPD hospitalizations

Hospital-discharge diagnoses in DoD, VA, and COSHPD hospital systems

Similar rates of hospitalization between deployed and nondeployed veterans

Age, sex, race (only for DoD PMR)

Able to assess only illnesses that resulted in hospitalization; possible undetected confounders PMR has lower sensitivity than a comparison of hospitalization rates would have

Smith et al., 2006 (Update)

Retrospective cohort study (cohort data from DMDC)

Active-duty personnel with a single deployment to: Gulf War theater (n = 455,465); southwest Asia, 1991-1998 (n = 249,047); Bosnia, 1995-1998 (n = 44,341)

Postdeployment hospitalization events (1991-2000)

Veterans of southwest Asia had slightly higher rate of hospitalization compared to deployed GWVs, while veterans of Bosnia had slightly lower rate of hospitalizations

Sex, age, marital status, pay grade, race/ethnicity, service branch, occupation, and predeployment hospitalization; time-dependent

Lower hazard ratio observed in veterans of Bosnia may be partially explained by shorter follow-up period Limitations: active-duty personnel only; hospitalizations at DoD facilities only

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