title: The Impact of Reporting a Prior Penicillin Allergy on the Treatment of Methicillin-Sensitive Staphylococcus aureus Bacteremia.
abstract: BACKGROUND
  Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection with mortality benefit from receipt of parenteral β-lactam therapy. A substantial portion of MSSA bacteremia patients report penicillin allergy, but infrequently have true allergy.
  
  
  OBJECTIVE
  To determine the frequency and predictors of optimal and adequate therapy in patients with MSSA bacteremia.
  
  
  METHODS
  Retrospective cohort.
  
  
  METHODS
  Adult inpatients with MSSA bacteremia, January 2009 through October 2013.
  
  
  METHODS
  The primary measure was a trial of optimal therapy (OT), defined as ≥3 inpatient days or discharge on any first-line agents (nafcillin, oxacillin, cefazolin, or penicillin G, if susceptible). The secondary measure was completion of adequate therapy (AT), defined as ≥10 inpatient days or discharge on an agent appropriate for MSSA bacteremia. Data were electronically gathered with key variables manually validated through chart review. Log-binomial regression models were used to determine the frequency and predictors of outcomes.
  
  
  RESULTS
  Of 456 patients, 346 (76%) received a trial of OT. Patients reporting penicillin allergy (13%) were less likely to receive OT trial than those without penicillin allergy (47% vs. 80%, p <0.001). Adjusting for other factors, penicillin allergy was the largest negative predictor of OT trial (RR 0.64 [0.49, 0.83]). Infectious Disease (ID) consultation was the largest positive predictor of OT trial across all patients (RR 1.34 [1.14, 1.57]). Allergy/Immunology consultation was the single most important predictor of OT trial among patients reporting penicillin allergy (RR 2.33 [1.44, 3.77]). Of 440 patients, 391 (89%) completed AT, with ID consultation the largest positive predictor of the outcome (RR 1.28 [1.15, 1.43]).
  
  
  CONCLUSIONS
  Nearly 25% of patients with MSSA bacteremia did not receive OT trial and about 10% did not receive AT completion. Reported penicillin allergy reduced, and ID consult increased, the likelihood of OT. Allergy evaluation, coupled with ID consultation, may improve outcomes in MSSA bacteremic patients.
authors.affiliation: Division of Rheumatology, Allergy, and Immunology, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America.|Medical Practice Evaluation Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America.|Harvard Medical School, Boston, Massachusetts, United States of America.|Edward P. Lawrence Center for Quality and Safety, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
authors.forename: Kimberly G
authors.identifier: http://orcid.org/0000-0003-4773-9817
authors.initials: KG
authors.lastname: Blumenthal
authors.affiliation: Medical Practice Evaluation Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America.|Harvard Medical School, Boston, Massachusetts, United States of America.|Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America.|Infection Control Unit, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
authors.forename: Erica S
authors.initials: ES
authors.lastname: Shenoy
authors.affiliation: Medical Practice Evaluation Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America.|Biostatistics Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
authors.forename: Mingshu
authors.initials: M
authors.lastname: Huang
authors.affiliation: Acadia Allergy and Immunology, Department of Medicine, University of South Carolina School of Medicine, Greenville, South Carolina, United States of America.
authors.forename: James L
authors.initials: JL
authors.lastname: Kuhlen
authors.affiliation: Edward P. Lawrence Center for Quality and Safety, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
authors.forename: Winston A
authors.initials: WA
authors.lastname: Ware
authors.affiliation: Medical Practice Evaluation Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America.|Harvard Medical School, Boston, Massachusetts, United States of America.|Biostatistics Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Parker
authors.affiliation: Medical Practice Evaluation Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America.|Harvard Medical School, Boston, Massachusetts, United States of America.|Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
authors.forename: Rochelle P
authors.initials: RP
authors.lastname: Walensky
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D016470:Bacteremia / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D004342:Drug Hypersensitivity / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008712:Methicillin / Q000009:adverse effects / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010406:Penicillins / Q000009:adverse effects* / Q000627:therapeutic use; D012189:Retrospective Studies; D012882:Skin Tests; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000472:pathogenicity; D014640:Vancomycin / Q000627:therapeutic use; D047090:beta-Lactams / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D010406:Penicillins; D047090:beta-Lactams; D014640:Vancomycin; D008712:Methicillin