Accounting for urgency: Implications of risk adjustment for surgical site infection after emergency colon surgery at safety net hospitals.

BACKGROUND

Colon operations performed for urgent indications or trauma are associated with a higher risk of surgical site infection. Prior models for surgical site infection surveillance did not account for this urgency, potentially yielding inadequate risk adjustment for surgical site infection at safety net hospitals that perform a disproportionate number of these emergency operations.

METHODS

We used data from the 2021 Healthcare Cost and Utilization Project State Inpatient and Emergency Department Databases from California and Florida. We evaluated index encounters during which colon surgery was performed, excluding hospitals performing <25 colon operations per year. We calculated risk- and reliability-adjusted surgical site infection rates, first adjusting for covariables modeled on the 2015 baseline National Healthcare Safety Network surgical site infection surveillance model, which did not account for trauma or emergency status: comorbidity index, diabetes, obesity, and endoscopic/laparoscopic approach; and subsequently adjusting for National Healthcare Safety Network-based covariables plus an indicator of emergency surgery. We then evaluated whether including this indicator affected the adjusted risk of surgical site infection among safety net hospitals and non-safety net hospitals.

RESULTS

We identified 360 hospitals that performed >25 colon operations in 2021, including 79 (22%) safety net hospitals. Safety net hospitals were more likely to be in the highest quintile of adjusted surgical site infection risk using the National Healthcare Safety Network-based covariates alone (P < .05) but not after adding the emergency surgery indicator to the model. The proportion of safety net hospitals in the highest quintile of adjusted surgical site infection risk decreased after accounting for emergency surgery.

CONCLUSION

Modifying risk adjustment models to include emergency status may reduce inadequate adjustment of surgical site infection risk after colon surgery, with important financial implications for safety net hospitals in the era of value-based incentives.