Delayed vs. Early Laparoscopic Appendectomy (DELAY) for Adult Patients with Acute Appendicitis

To assess whether delaying appendectomy until the following morning is non-inferior to immediate surgery in those with acute appendicitis presenting at night.Despite a lack of supporting evidence, those with acute appendicitis who present at night frequently have surgery delayed until the following morning.The delay trial is a non-inferiority randomized controlled trial conducted between 2018 - 22 at two tertiary care hospital in Canada. Adults with imaging confirmed acute appendicitis who presented at night (2000 - 0400). Delaying surgery until after 0600 was compared with immediate surgery. The primary outcome was 30 day post operative complications. An a prior non-inferiority margin of 15% was deemed clinically relevant.127 of a planned 140 patients were enrolled in the DELAY trial (59 in the delayed group, 68 in the immediate group). The two groups were similar at baseline. The mean time between decision to operate and surgery was longer in the delayed group (11.0 hours vs. 4.4 hours, P<0.0001). The primary outcome occurred in 6/59 (10.2%) of those in the delayed group versus 15/67 (22.4%) of those in the immediate group (P=0.07). The difference between groups met the a priori non-inferiority criteria of +15% (risk difference -12.2%, 95%CI -24.4% to +0.4%, test of non-inferiority P<0.0001).The DELAY study is the first trial to assess delaying appendectomy in those with acute appendicitis. We demonstrate non-inferiority of delaying surgery until the following morning.This trial was registered with ClinicalTrials.gov (NCT03524573).