Changes in Emergency General Surgery Volume Within Military Treatment Facilities (2016-2023)

Emergency General Surgery (EGS) procedures are vital and high-risk interventions. Delivery of these procedures in military treatment facilities (MTFs) is important to beneficiaries of the U.S. Military Health System (MHS). Organizational changes, including consolidation of MTFs under the Defense Health Agency and personnel reductions, in conjunction with the COVID-19 pandemic, have led to concerns about potential declines in care quality. We assessed whether clinical outcomes remained consistent or were negatively influenced by the healthcare administrative changes and the COVID-19 pandemic.

Claims data from the MHS Data Repository and ICD-10 diagnosis codes were used to identify patients, 18-64, admitted to U.S.-based MTFs between fiscal years 2016 and 2023 with an EGS condition. The main predictor was hospital EGS volume categorized into volume-based quartiles. Outcomes were 30-day mortality, complications, and readmissions. Patients were stratified into 2 time periods (FY 2016-2019 and FY 2020-2023) based on index admission date. Multivariable logistic regression models were used to assess the relationship between MTF volume and clinical outcomes.

113,626 EGS encounters treated across 40 MTFs were identified. Adjusted analyses showed that compared to the highest volume MTFs of 2016-2019, MTFs in the lower middle quartiles (LMQ) and upper middle quartiles (UMQ) of 2016-2019 (OR: 0.67; OR: 0.67) and LMQ of 2020-2023 (OR: 0.70) had a significantly decreased likelihood of 30-day mortality. Compared to 2016-2019's highest volume MTFs, the lowest volume MTFs of 2016-2019 were significantly less likely to experience complications (OR: 0.67), while MTFs from the UMQ of 2016-2019 (OR: 1.10) and all quartiles of 2020-2023 (OR: 1.22; OR: 1.61; OR: 1.43; OR: 1.27) were significantly more likely to develop complications. Patients treated at MTFs in the LMQ and UMQ of 2016-2019 (OR: 0.78; OR: 0.70) and those in the lowest and middle quartiles of 2020-2023 (OR: 0.67; OR: 0.71; OR: 0.76) had a significantly lower likelihoods of readmission compared to the highest volume MTFs of 2016-2019.

The likelihood of 30-day complications among all MTF quartiles in 2020-2023 was significantly higher compared to MTFs in 2016-2019. However, EGS patients treated in low-volume MTFs experienced similar, if not improved, clinical outcomes of mortality and readmissions compared to those treated in high-volume MTFs.