SAPPHIRE
Research type
Research Study
Full title
Safe Antimicrobial ProPhylaxis for surgery study
IRAS ID
282161
Contact name
Tom Abbott
Contact email
Sponsor organisation
Barts Heath NHS Trust
Duration of Study in the UK
1 years, 6 months, 1 days
Research summary
Surgical site infection (SSI) affects 1 in 20 surgical patients and is an important cause of avoidable postoperative morbidity. The widespread use of antimicrobial drugs to prevent SSI is standard practice worldwide. However, the evidence supporting antimicrobial prophylaxis is relatively weak, and was generated before the introduction of modern surgical and anaesthetic techniques, which reduce rates of SSI. Antimicrobial use may also cause harm, with 1 in 50 surgical patients suffering complications directly attributable to antimicrobial drugs, including acute kidney injury, hearing loss and anaphylaxis. In addition, 1 in 7 patients carry a label of antimicrobial allergy , which results in the use of alternative antimicrobial drugs that are less effective and more toxic, potentially leading to more side effects. At a societal level, the widespread use of antimicrobial drugs is the principal cause of antimicrobial resistance, which represents a serious threat to global healthcare. We hypothesise that current practice for surgical antimicrobial prophylaxis may not be based on robust evidence of benefit versus risk. We will determine whether there are 1) association s between the number of doses of antimicrobial drugs and incidence of SSI, mortality and hospital re -admission within 30 days after surgery; and 2) associations between these outcomes and the presence of antimicrobial allergy labels.
Lay summary of study results: Many people who come to hospital for surgery say they are allergic to one or more medicines, but in most cases, these are not true allergies. The most common labels are for antibiotics. Avoiding these first-choice drugs can mean patients are treated with less effective alternatives, which might increase the risk of complications after surgery.
We carried out a study in 21 NHS hospitals between March 2022 and October 2024. We included over 13,000 adult patients having one of six common types of surgery. We compared patients who had a drug allergy label with those who did not. We looked for problems that occurred in the 30 days after surgery, including infections, allergic reactions, and deaths.
Nearly one in three patients (29%) had at least one drug allergy label. Patients with these labels were more likely to have complications after surgery (25% compared to 20% of those without a label). They were also more likely to develop infections, including surgical site infections. True allergic reactions to medicines were rare, but slightly more common in patients with allergy labels. The risk of death was the same in both groups.
Our findings show that most drug allergy labels are incorrect, but they are linked to worse outcomes after surgery. Identifying and removing incorrect allergy labels could help improve recovery and reduce complications for many patients.REC name
Yorkshire & The Humber - Bradford Leeds Research Ethics Committee
REC reference
22/YH/0040
Date of REC Opinion
7 Feb 2022
REC opinion
Favourable Opinion