Differences in Disease Non-battle Injury Between Combatant Commands

Introduction: Disease and non-battle injury (DNBI) have historically been a major or primary medical burden in expeditionary military populations. The United States has multiple deployed populations conducting operations across the world. This study aims to determine if DNBI rates are different between military populations by comparing the United States Africa Command (USAFRICOM) and United States Central Command (USCENTCOM) areas of responsibility. Materials and Methods: The study period was from January 1, 2017 to December 31, 2021. Individual evacuation data including date, necessary specialty care, and combatant command (CCMD) were acquired via United States Transportation Command Regulating and Command & Control Evacuation System. Total population data was acquired from USAFRICOM and USCENTCOM headquarters. Total inpatient and outpatient encounters at each CCMD were acquired via Theater Medical Data Store. The proportions and evacuation rates of DNBI types within USAFRICOM and USCENTCOM were compared. Results: USCENTCOM had significantly higher proportions of outpatient and inpatient services for mental disorders, musculoskeletal diseases, and neurologic conditions compared to USAFRICOM. USCENTCOM had a significantly lower evacuation rate compared to USAFRICOM for every year analyzed: 2017 (P-value < .0001; relative risk [RR] = 0.834; 95% CI = 0.80-0.87), 2018 (P-value < .0001; RR = 0.818; 95% CI = 0.78-0.85), 2019 (P-value < .0001; RR = 0.785; 95% CI = 0.75-0.82), 2020 (P-value < .0001; RR = 0.889; 95% CI = 0.84-0.94), and 2021 (P-value < .0001; RR = 0.868; 95% CI = 0.83-0.91). Conclusions: The evacuation rates of different categories of DNBI vary between CCMDs. There will be CCMD-specific factors that impact the effectiveness of initiatives to reduce the DNBI burden.