Disease and nonbattle injuries sustained by a U.S. Army Brigade Combat Team during Operation Iraqi Freedom

A longitudinal cohort analysis of disease nonbattle injuries (DNBI) sustained by a large combat-deployed maneuver unit has not been performed. A descriptive analysis was undertaken to evaluate for DNBI casualty care statistics incurred by a U.S. Army Brigade Combat Team (BCT) during a counterinsurgency campaign of Operation Iraqi Freedom. Of the 4,122 soldiers deployed, there were 1,324 DNBI with 5 (0.38%) deaths, 208 (15.7%) medical evacuations (MEDEVAC), and 1,111 (83.9%) returned to duty. The DNBI casualty rate for the BCT was 257.0/1,000 soldier combat-years. Females, compared with males, had a significantly increased incidence rate ratio for becoming a DNBI casualty 1.67 (95% CI 1.37, 2.04). Of 47 female soldiers receiving MEDEVAC 35 (74%) were for pregnancy-related issues. Musculoskeletal injuries (50.4%) and psychiatric disorders (23.3%) were the most common body systems involved with DNBI casualties. Among the BCT cohort the psychiatric DNBI casualty rate and suicide rate were 59.8 and 0.58 per 1,000 soldier combat-years. The BCT cohort incidence rates for common musculoskeletal injuries per 1,000 combat-years were as follows: ankle sprain 15.3, anterior cruciate ligament rupture 3.3 and shoulder dislocation 1.2. Musculoskeletal injuries and psychiatric disorders accounted for 74% of the total DNBI casualties, and 43% of the DNBI casualties requiring subsequent MEDEVAC. The BCT cohort had a suicide rate nearly four times greater than previously reported, and selected musculoskeletal injury incidence rates were fivefold greater than the general population.