Acute Care Surgery Model and Outcomes in Emergency General Surgery

Annually, more than 2 million patients are admitted with emergency general surgery (EGS) conditions. Emergency general surgery cases comprise 11% of all general surgery operations, yet account for 47% of mortalities and 28% of complications. Using the statewide general surgery Michigan Surgical Quality Collaborative (MSQC) data, we previously confirmed that wide variations in EGS outcomes were unrelated to case volume/complexity. We assessed whether patient care model (PCM) affected EGS outcomes.

There were 34 hospitals that provided data for PCM, resources, surgeon practice patterns, and comprehensive MSQC patient data from January 1, 2008 to December 31, 2016 (general surgery cases = 126,494; EGS cases = 39,023). Risk and reliability adjusted outcomes were determined using hierarchical multivariable logistic regression analysis with multiple clinical covariates and PCM.

The general surgery service (GSS) model was more common (73%) than acute care surgery (ACS, 27%). Emergency general surgery 30-day mortality was 4.1% (intestinal resections 11.6%). The ACS model was associated with a reduction of 31% in mortality (odds ratio [OR] 0.69; 95% CI 0.52-0.92] for EGS cases, related to decreased mortality in the intestinal resection cohort (8.5% ACS vs 12% GSS, p < 0.0001). Morbidity in EGS was 17.4% (9.7% elective); highest (40%) in intestinal resection, and PCM did not affect morbidity. We identified specific variables for an optimal EGS risk adjustment model.

This is the first multi-institutional study to identify that an ACS model is associated with a significant 31% mortality reduction in EGS using prospectively collected, clinically obtained, research-quality collaborative data. We identified that new risk adjustment models are necessary for EGS outcomes evaluations.