Long-term Outcomes following Nonoperative Management of Acute Appendicitis: A Population-based Analysis

To describe long-term representations and interventions following nonoperative management (NOM) of acute appendicitis (AA).

Trial data suggest NOM of AA carries a substantial risk of subsequent appendectomy, although NOM is increasingly offered to patients. Population-based data is required to understand the real-world long-term course of patients undergoing NOM of AA.

This population-based cohort study included all adult patients in Ontario, Canada who presented to any emergency department (ED) with AA between 2004 and 2019. Patients who did not undergo a procedure on index ED presentation or hospital admission were defined as NOM and followed for 5 years. The cumulative incidence of composite representation or intervention (ED representation, readmission, emergency, or scheduled appendicitis procedure) was calculated accounting for the competing risk of death.

Of 156,362 patients identified with AA, 13,200 underwent NOM. The cumulative incidence of composite representation or intervention was 33% at 1 year (95% CI: 32%-33%) and 36% at 5 years (95% CI: 36%-37%). At 5 years, the incidence of appendicitis-specific ED representation or hospital readmission was 16% (95% CI: 15%-16%), the incidence of an emergency procedure for AA was 12% (95% CI: 12%-13%), and the incidence of scheduled surgery was 21% (95% CI: 20%-21%). In a subgroup of patients with uncomplicated AA, composite representation or intervention were 28% at 1 year (95% CI: 27%-29%) and 32% at 5 years (95% CI: 32%-33%).

Real-world estimates of emergency representation with or without urgent surgery following NOM of AA were lower than previously described. Scheduled appendectomy made up an important proportion of long-term interventions following NOM.