Outcomes following out-of-hours acute appendectomy: a systematic review and meta-analysis

Appendicitis is one of the most common emergency diseases. Currently, it is unclear whether there are differences in performing appendectomy during in-hour (IH) versus out-of-hour (OH). A comprehensive search for studies that compared IH and OH was conducted in Web of Science, PubMed and EMBASE. Data of including studies were subjected to meta-analysis. The study was registered on PROSPERO (CRD42023467592). The result indicated that the OH group had more complicated appendicitis (OH 25.1% vs. IH 24.5%, RD = 0.02; 95% CI, 0.00 to 0.05; p = 0.04, I2 = 72%), higher level of C-reactive reaction protein (OH 44.88 ± 16.14 vs. IH 41.19 ± 16.50, MD = 12.15; 95% CI, 2.28 to 22.01; p = 0.02, I2 = 100%) and higher rate of conversion to open surgery {OH 8.0% vs. IH 7.8%, RD = 0.02; 95% CI, 0.00 to 0.03; p = 0.02, I2 = 93%. 95% Predictive interval (PI), -0.04 to 0.08}. No significant differences were observed in operative time, length of hospital stay, surgical site infection rates, readmission, reintervention, or the distribution of Clavien-Dindo grades1-2 and3-4 complications. Thirty-day mortality and overall mortality were also comparable. OH appendectomy does not affect perioperative complications or mortality in patients with appendicitis compared to IH. These results should be interpreted cautiously due to the limited number of available studies. 1. The out-of-hour appendectomy may not affect the perioperative complications and mortality of appendicitis patients compared with in-hour appendectomy. 2. Patients that accepted out-of-hour appendectomy have a higher level of CRP and a higher proportion of complicated appendicitis.