Transferred Emergency General Surgery Patients Are at Increased Risk of Death: A NSQIP Propensity Score Matched Analysis

BACKGROUND: Emergency general surgery (EGS) encompasses high-risk patients undergoing high-risk procedures. Admission source, particularly interhospital transfer, is rarely accounted for in clinical performance benchmarking. Our goal was to assess the impact of transfer status on outcomes after EGS. STUDY DESIGN: This was a retrospective analysis of the American College of Surgeons NSQIP database (2005 to 2014). All inpatients that underwent 1 of 7 EGS procedures shown to represent 80% of EGS volume, complications, and mortality nationally were included. Admission source was classified as directly admitted vs transferred from an outside emergency department or an acute care facility. The primary outcomes were overall mortality, overall morbidity, and major morbidity. A 3:1 propensity score matched analysis was used to determine the association of admission source with outcomes. Subgroup analysis was performed for high- and low-risk EGS procedures. RESULTS: A total of 222,519 EGS admissions were identified, of which 15,232 (6.8%) were transfers. Mean age was 46 years and 51.4% were female. Overall mortality was 3.1% for the entire cohort and 10.8% within the transfer group. After propensity score matched analysis for 33 clinical and demographic variables, transferred patients had higher rates of overall mortality (odds ratio 1.01; 95% CI 1.01 to 1.02), higher overall morbidity (odds ratio 1.07; 95% CI 1.05 to 1.09), and major morbidity (odds ratio 1.06; 95% CI 1.04 to 1.08) compared with directly admitted patients. CONCLUSIONS: After rigorous risk adjustment, interhospital transfer status has a small effect on mortality and morbidity in the EGS population. This could suggest that it is reasonable to transfer patients and that regionalization of care should be encouraged.