# Weekend Effect and Mortality After Emergency Laparotomy: A Retrospective Cohort Study With Complimentary Meta‐Analysis

## TL;DR

This study found no difference in 30-day mortality for emergency laparotomy patients operated on weekends versus weekdays.

## Contribution

The study provides high-certainty evidence that the weekend effect does not impact mortality after emergency laparotomy.

## Key findings

- No difference in 30-day mortality between weekend and weekday emergency laparotomy patients (OR: 1.04, 95% CI 0.87–1.25).
- Patient characteristics were comparable between the two groups, including age, sex, and surgical complexity.
- High certainty of evidence was achieved through a robust meta-analysis and retrospective cohort study.

## Abstract

To evaluate the prognostic significance of the weekend effect in patients undergoing emergency laparotomy.

A STROCSS‐compliant retrospective cohort study (in three centres between January 2014 and January 2022) with complementary PRISMA‐compliant meta‐analysis (last search on 10 February 2025) was conducted. All adult patients undergoing non‐traumatic emergency laparotomy were considered eligible. Emergency laparotomy during weekends (Saturday, Sunday and public holidays) was the prognostic factor of interest, and emergency laparotomy during weekdays (Monday, Tuesday, Wednesday, Thursday and Friday) was the comparison. Thirty‐day mortality was the outcome.

The cohort study included 1952 patients and a search of electronic databases identified five retrospective cohort studies including 5374 patients. Consequently, 7326 patients (weekend group: 2035; weekdays group: 5291) were included for analyses. Both groups were comparable in terms of median age (67 years vs. 65, p = 0.194), being an octogenarian (17.9% vs. 17.9%, p = 0.970), male sex (41.9% vs. 45.7%, p = 0.153), ASA I status (4.5% vs. 6.7%, p = 0.080), ASA II (33.6% vs. 35.2%, p = 0.524), ASA III (46.6% vs. 41.6%, p = 0.060), ASA IV (14.7% vs. 15.2%, p = 0.764), ASA V (0.6% vs. 1.3%, p = 0.249), need for bowel resection (54.0% vs. 57.6%, p = 0.172) and peritoneal contamination (26.4% vs. 29.2%, p = 0.236). There was no difference in the risk of 30‐day mortality between the two groups (OR: 1.04, 95% CI 0.87–1.25, p = 0.650; I
2 = 0%). The GRADE certainty was high.

Robust evidence with high certainty suggests that the weekend effect does not influence the risk of mortality after emergency laparotomy. This could be explained by the standardisation of perioperative care in patients undergoing emergency laparotomy.