Title: Improving safety for surgical patients through better diagnosis of drug allergies
Funder: Department of Health and Social Care

Abstract: Research questionCan we improve the diagnostic pathways for surgical patients with possible drug allergies? BackgroundAllergic reactions during surgery, commonly caused by muscle-relaxant drugs, antibiotics, and skin cleaning solutions, are the most serious and life-threatening of all allergic reactions. Failure to adequately diagnose the cause of these reactions, which affect up to 1000 patients every year, creates significant uncertainty about the safety of future surgery. In parallel to this problem an estimated 1.5 million NHS surgical patients each year carry a label of drug allergy. The majority of these labels are incorrect, with most patients having experienced reactions which were pharmacological side-effects of the drug, or having been given the label incorrectly because of a family history of allergy to this drug. Evidence suggests that patients falsely labelled with drug allergies may receive sub-optimal perioperative care leading to worse outcomes. However, a critical shortage of allergy specialists makes it impossible to test every patient in an allergy clinic. It is imperative that we develop novel diagnostic pathways which improve safety for all patients with a possible drug allergy.Objectives Confirm whether surgical patients with drug allergy labels experience more postoperative complications. Describe patients' and healthcare professionals' understanding of perioperative allergy. Determine whether a clinical decision support tool could allow non-allergist healthcare professionals working in preoperative assessment clinics to triage patients with a penicillin allergy label into the appropriate diagnostic pathway. Define the unmet need for highly specialised drug provocation testing in patients who experience life-threatening perioperative reactions suspected to be due to allergy, and the cost of delivering this service nationally.MethodsI will conduct an observational study of 18,000 patients undergoing major surgery to identify associations between drug allergy labels and postoperative complications. I will conduct qualitative research amongst patients and healthcare professionals to better understand their views and attitudes towards drug allergy. In a proof of concept study, I will examine the use of a clinical decision support tool (CDST) by non-allergist healthcare professionals working in the preoperative assessment clinic, to triage patients with penicillin allergy labels. Lastly, I will conduct a national survey of NHS Trusts providing perioperative allergy services to define the unmet need for highly specialised drug provocation testing and conduct a health economic analysis to establish the cost of providing this service at a national level.Timelines for deliveryWorkstream1: months 1-30 Workstream 2: months 1-24 Workstream 3: months 12-30Workstream 4: months 1-18Development of information resources: months 21-33 Thesis preparation and submission: months 27-36Impact and disseminationThis fellowship will redefine drug allergy diagnosis for around 1.5 million NHS surgical patients each year, providing a template for novel solutions to diagnose genuine, life-threatening drug allergies as well diagnosing false allergy labels. By understanding the fears and concerns amongst patients and healthcare professionals around perioperative drug allergy, I will ensure these solutions are patient-centred and acceptable. I will co-design, with patient researchers, a package of information materials and disseminate my findings via scientific reports as well as mainstream and social media.

Lay abstract: BackgroundAllergies are increasingly common in society and patients report allergy to medicines much more frequently. My fellowship focuses on the diagnosis of allergy to medicines in surgical patients. This is a two-fold problem. Firstly, around 1000 patients every year suffer life-threatening reactions to medicines used during surgery which might be due to allergy. Up to one in 10 of these patients will die in the operating theatre, and survivors suffer long-term health problems including post-traumatic stress disorder. Making a diagnosis can be very difficult. The best test for medicine allergy is to give the medicine and check for symptoms, but for powerful anaesthetic drugs this can only be done by an anaesthetist with allergy expertise. Specialists like this are rare in the UK. Secondly, 1.5 million NHS patients undergoing surgery every year carry a label of medicine allergy. Seven out of ten of these patients don't have an allergy at all, but experienced side-effects of a medicine which were misinterpreted as allergy by the patient, their nurse or doctor. Sometimes, an allergy label is mistakenly given to a patient because a family member has that allergy, even though the patient themselves has never taken the medicine. The label obliges doctors to use alternative medicines during and after surgery which could be less effective and have more side-effects. Patients are placed at risk of worse treatment outcomes for no good reason. These two allergy problems are linked, because fear of life-threatening allergy drives the (incorrect) over-diagnosis of medicine allergy. Patients and healthcare professionals often argue that it's better to 'be on the safe side' and simply avoid medicines, even though true allergy isn't confirmed. Currently, there aren't enough specialist allergy doctors to test all patients labelled with medicine allergy, so patients keep their labels and may suffer avoidable harm as a result. The shortage of allergy doctors also means we cannot perform the very specialised tests needed when patients suffer life-threatening allergic reactions during surgery. Patients may not be able to have surgery in the future because we don't know which medicines can be given safely. Many patients are so worried that they avoid surgery altogether. This can be extremely serious, for example if life-saving cancer surgery is required. Research methodsIn this fellowship I will tackle both of the problems with drug allergy diagnosis in surgical patients. My proposal has four parts. Firstly, I will confirm whether NHS patients labelled as allergic to a medicine experience worse treatment outcomes after surgery than those with no allergy label. This UK-wide study will use data from 18,000 patients undergoing major surgery, measuring outcomes including wound infections and death in the six months after surgery. Secondly, I will interview patients who have medicine allergy labels, to understand their views and concerns about the perceived allergy. I will also interview healthcare professionals involved in the care of surgical patients, including anaesthetists, surgeons and nurses. Understanding all these views is key to developing new strategies for diagnosing allergy to medicines. Thirdly, I will look at a new pathway which allows patients to be given an accurate allergy diagnosis ahead of their surgery. This involves a simple decision-support tool, used by staff in the preoperative assessment clinic who have no specialist allergy training. Lastly, I will find out how many patients each year might benefit from highly specialised allergy testing having experienced life-threatening medicine reactions during surgery, and determine the cost of providing this service nationally. Working with patients, healthcare professionals and health policy-makers, I will disseminate my findings across the NHS to re-design patient care for those affected by this important but neglected problem.

Research activity codes: 7.3 MANAGEMENT AND DECISION MAKING
Health categories: INFLAMMATORY AND IMMUNE SYSTEM