Out-of-Hours Appendicectomy Is Associated With Earlier Theatre Access and Comparable Clinical Outcomes in a UK Tertiary Centre.

Background Acute appendicitis is one of the most common surgical emergencies and a frequent indication for emergency abdominal surgery. Concerns regarding reduced staffing, competing emergency workload and limited overnight theatre availability have contributed to ongoing debate regarding outcomes following surgery outside routine working hours. Contemporary UK tertiary-centre data remain limited. This study evaluated the association between operative timing, theatre access and short-term clinical outcomes following emergency appendicectomy. Methods A retrospective cohort study was conducted at a UK tertiary centre, including all adults undergoing emergency appendicectomy between January and June 2025. Patients were categorised according to operative start time as in-hours (08:00-17:30) or out-of-hours (17:31-07:59). Data included age, American Society of Anesthesiologists (ASA) Physical Status Classification score, imaging-defined disease severity, time from radiological diagnosis to theatre, length of hospital stay (LOS), postoperative complications and 30-day hospital re-presentations. Continuous variables were assessed for normality using the Shapiro-Wilk test and compared using the Mann-Whitney U test. Categorical variables were compared using Pearson's chi-square test or Fisher's exact test where appropriate. Results A total of 127 patients were included: 69 in-hours and 58 out-of-hours. Mean age was 43.2 ± 18.2 and 44.9 ± 19.3 years, respectively (Mann-Whitney U = 1900.5, p = 0.628). Median ASA score was 2 (interquartile range (IQR) 1-2) in both cohorts (p = 0.686). Imaging-defined complicated appendicitis occurred in 32/69 (46.4%) and 28/58 (48.3%) patients, respectively (p = 0.972). Mean time from radiological confirmation to surgery was 22.9 ± 24.4 hours in-hours and 16.0 ± 14.0 hours out-of-hours (Mann-Whitney U = 2372.0, p = 0.073). Median LOS was 2 (IQR 1-4) and 2 (IQR 1-3) days, respectively (p = 0.430). Postoperative complications occurred in 11/69 (15.9%) and 12/58 (20.7%) patients, respectively (p = 0.489), while 30-day hospital re-presentations occurred in 9/69 (13.0%) and 7/58 (12.1%), respectively (p = 0.869). Overall, 23/127 (18.1%) patients experienced at least one postoperative complication; intra-abdominal collection was the most common, occurring in 11/127 (8.7%). Sixteen patients (12.6%) re-presented within 30 days, including seven hospital readmissions and nine Surgical Same Day Emergency Care (SDEC) reviews. Two patients required conversion to open right hemicolectomy for severe complicated appendicitis with caecal involvement. Conclusions No statistically significant differences were observed between in-hours and out-of-hours appendicectomy in time from radiological confirmation to surgery, postoperative complications, LOS or 30-day hospital re-presentation. Within this cohort, no difference in measured short-term outcomes was detected according to operative timing. Larger multicentre studies are required to assess whether these findings are consistent across different emergency surgical settings and to account for theatre availability, staffing and case prioritisation.