Original article Impact of postoperative non-steroidal anti-inflammatory drugs on adverse events after gastrointestinal surgery STARSurg Collaborative* Correspondence to: Mr A. Bhangu, Academic Department of Surgery, Room 29, 4th Floor, Queen Elizabeth Hospital, Edgbaston, Birmingham B15 2TH, UK (e-mail: aneelbhangu@doctors.org.uk) Background: Recent evidence has suggested an association between postoperative non-steroidal anti-inlammatory drugs (NSAIDs) and increased operation-speciic complications. This study aimed to determine the safety proile following gastrointestinal surgery across a multicentre setting in the UK. Methods: This multicentre study was carried out during a 2-week interval in September–October 2013. Consecutive adults undergoing elective or emergency gastrointestinal resection were included. The study was powered to detect a 10 per cent increase in major complications (grade III–V according to the Dindo–Clavien classiication). The effect of administration of NSAIDs on the day of surgery or the following 2days was risk-adjusted using propensity score matching and multivariable logistic regression to produce adjusted odds ratios (ORs). The type of NSAID and the dose were registered. Results: Across 109 centres, early postoperative NSAIDs were administered to 242 (16⋅1 per cent) of 1503 patients. Complications occurred in 981 patients (65⋅3 per cent), which were major in 257 (17⋅1 per cent) and minor (Dindo–Clavien grade I–II) in 724 (48⋅2 per cent). Propensity score matching created well balanced groups. Treatment with NSAIDs was associated with a reduction in overall complications (OR 0⋅72, 95 per cent conidence interval 0⋅52 to 0⋅99; P = 0⋅041). This effect predominately comprised a reduction in minor complications with high-dose NSAIDs (OR 0⋅57, 0⋅39 to 0⋅89; P = 0⋅009). Conclusion: Early use of NSAIDs is associated with a reduction in postoperative adverse events following major gastrointestinal surgery. ∗ Co-authors can be found under the heading Collaborators Paper accepted 18 June 2014 Published online in Wiley Online Library (www.bjs.co.uk). DOI: 10.1002/bjs.9614 Introduction Non-steroidal anti-inlammatory drugs (NSAIDs) are used as part of analgesic regimens after gastrointestinal surgery, and are recommended by the Enhanced Recovery After Surgery (ERAS ® ) Society 1 . This is a major issue for patients, doctors and commissioners, on a background of more than 200 million major operations worldwide per year 2 . NSAIDs used as analgesics have an opiate-sparing role, which may aid recovery by enhancing return of bowel function, reducing length of hospital stay and potentially reducing complications 1,3,4 . Long-term NSAID use is associated with cardiovascular and gastrointestinal side-effects, although short-term use may not place patients at these risks 5,6 . Although reduced collagen synthesis and microthrombus or embo- lus formation may explain adverse events, prostaglandin inhibition and anti-inlammatory effects may be beneicial after surgery 7,8 . However, recent evidence 9 – 12 has linked postoperative use of NSAIDs with increased surgical com- plications following gastrointestinal resection, including anastomotic leak. A study analysing general complication proiles in surgi- cal patients who have received early postoperative NSAIDs is lacking. This study aimed to determine the safety pro- ile of postoperative NSAIDs after major gastrointestinal resection in current UK practice. Methods This study was carried out according to a prespeciied protocol. The protocol was reviewed by the national research ethics service and a research ethics committee, which conirmed that the anonymous, observational nature of data collection meant that this cohort study did not require research registration. Each participating centre was © 2014 BJS Society Ltd BJS Published by John Wiley & Sons Ltd