Table. Primary Outcome Definitions.

Source	Definition of treatment success
CODA Collaborative,8 2020	30-d Health status, as assessed with the use of the European Quality-of-Life 5-Dimensions questionnaire.
Livingston et al,9 2018	Resolution of acute appendicitis resulting in discharge from the hospital without the need for surgical intervention and no recurrent appendicitis during a minimum follow-up of 1 y.
Styrud et al,16 2006	Resolution of appendicitis symptoms in 24 h and absence of recurrence, pain, and complications at up to 1 y of follow-up.
Vons et al,15 2011	The rate of peritonitis that occurred within 30 d of treatment initiation.
Ceresoli et al,17 2019	Success rate of the treatment, defined as the resolution of symptoms (no abdominal pain or fever) and resolution of inflammatory markers (white blood cell count <10 000/μLa and C-reactive protein <1 mg/dLb) within 2 wk after appendectomy in the surgical arm or from the third dose of ertapenem without other treatments in the antibiotic arm.
O’Leary et al,6 2021	The primary end point for the trial evaluated the success rate of antibiotic treatment only for acute uncomplicated appendicitis at 1-y follow-up. In the operative treatment arm, the primary end point was defined as successful appendectomy, which was expected to be 100%.
Ericksson et al,18 1995	Resolution of pain and decrease in white blood cell count and C-reactive protein.
Hansson et al,192009	Efficacy for antibiotic treatment was defined as definite improvement without the need for surgery within a median follow-up of 1 y. Efficacy for surgical treatment was confirmed appendicitis at operation or another appropriate surgical indication for operation.

^a To convert to ×10⁹/L, multiply by 0.001.

^b To convert to mg/L, multiply by 10.