title: The revolving door: antibiotic allergy labelling in a tertiary care centre.
abstract: BACKGROUND
  Patients frequently report antibiotic allergies; however, only 10% of labelled patients have a true allergy.
  
  
  OBJECTIVE
  We investigated the documentation of antibiotic 'allergy' labels (AAL) and the effect of labelling on clinical outcomes, in a West Australian adult tertiary hospital.
  
  
  METHODS
  Retrospective cross-sectional analysis of patients captured in the 2013 and 2014 National Antimicrobial Prescribing Surveys was carried out. Data were collected on documented antibiotic adverse drug reactions, antibiotic cost, prescribing appropriateness, prevalence of multi-drug resistant organisms, length of stay, intensive care admission and readmissions.
  
  
  RESULTS
  Of the 687 patients surveyed, 278 (40%) were aged 70 or above, 365 (53%) were male and 279 (41%) were prescribed antibiotics. AAL were recorded in 122 (18%) patients and the majority were penicillin labels (n = 87; 71%). Details of AAL were documented for 80 of 141 (57%) individual allergy labels, with 61 describing allergic symptoms. Patients with beta-lactam allergy labels received fewer penicillins (P = 0.0002) and more aminoglycosides (P = 0.043) and metronidazole (P = 0.021) than patients without beta-lactam labels. Five patients received an antibiotic that was contraindicated according to their allergy status. Patients with AAL had significantly more hospital readmissions within 4 weeks (P = 0.001) and 6 months (P = 0.025) of discharge, compared with unlabelled patients. The majority (81%) of readmitted labelled patients had major infections.
  
  
  CONCLUSIONS
  AAL are common, but poorly documented in hospital records. Patients with AAL are significantly more likely to require alternative antibiotics and hospital readmissions. There may be a role for antibiotic allergy delabelling to mitigate the clinical and economic burdens for patients with invalid allergy labels.
authors.affiliation: Department of Clinical Immunology, Royal Perth Hospital, Perth, Western Australia, Australia. brittany.knezevic@health.wa.gov.au.
authors.forename: B
authors.initials: B
authors.lastname: Knezevic
authors.affiliation: Department of Clinical Immunology, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: D
authors.initials: D
authors.lastname: Sprigg
authors.affiliation: Department of Research, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Seet
authors.affiliation: Department of Research, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.|Centre for Applied Statistics, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Trevenen
authors.affiliation: Department of Infectious Diseases, Austin Health, Melbourne, Victoria, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Trubiano
authors.affiliation: Department of Immunology, Royal Adelaide Hospital, Adelaide, South Australia, Australia.
authors.forename: W
authors.initials: W
authors.lastname: Smith
authors.affiliation: School of Medicine and Pharmacology, Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia.
authors.forename: Y
authors.initials: Y
authors.lastname: Jeelall
authors.affiliation: Drug Allergy Working Party, Australasian Society of Clinical Immunology and Allergy, Sydney, New South Wales, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Vale
authors.affiliation: Department of Clinical Immunology, Princess Margaret Hospital, Perth, Western Australia, Australia.|Pathwest Laboratory, Queen Elizabeth II Campus, Perth, Western Australia, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Loh
authors.affiliation: Department of Clinical Immunology, Royal Perth Hospital, Perth, Western Australia, Australia.|Pathwest Laboratory, Queen Elizabeth II Campus, Perth, Western Australia, Australia.
authors.forename: A
authors.initials: A
authors.lastname: McLean-Tooke
authors.affiliation: Department of Clinical Immunology, Royal Perth Hospital, Perth, Western Australia, Australia.|Pathwest Laboratory, Queen Elizabeth II Campus, Perth, Western Australia, Australia.|Department of Clinical Immunology, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.|Institute for Immunology and Infectious Diseases, Murdoch University, Perth, Western Australia, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Lucas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000145:classification; D001315:Australia / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004282:Documentation; D004342:Drug Hypersensitivity / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010359:Patient Readmission / Q000706:statistics & numerical data*; D010406:Penicillins / Q000009:adverse effects*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D062606:Tertiary Care Centers
chemical_list: D000900:Anti-Bacterial Agents; D010406:Penicillins
keywords: allergy; antibiotic; delabelling; hypersensitivity; penicillin