title: Accuracy of diagnosis codes to identify febrile young infants using administrative data.
abstract: BACKGROUND
  Administrative data can be used to determine optimal management of febrile infants and aid clinical practice guideline development.
  
  
  OBJECTIVE
  Determine the most accurate International Classification of Diseases, Ninth Revision (ICD-9) diagnosis coding strategies for identification of febrile infants.
  
  
  METHODS
  Retrospective cross-sectional study.
  
  
  METHODS
  Eight emergency departments in the Pediatric Health Information System.
  
  
  METHODS
  Infants aged <90 days evaluated between July 1, 2012 and June 30, 2013 were randomly selected for medical record review from 1 of 4 ICD-9 diagnosis code groups: (1) discharge diagnosis of fever, (2) admission diagnosis of fever without discharge diagnosis of fever, (3) discharge diagnosis of serious infection without diagnosis of fever, and (4) no diagnosis of fever or serious infection.
  
  
  METHODS
  The ICD-9 diagnosis code groups were compared in 4 case-identification algorithms to a reference standard of fever ≥100.4°F documented in the medical record.
  
  
  METHODS
  Algorithm predictive accuracy was measured using sensitivity, specificity, and negative and positive predictive values.
  
  
  RESULTS
  Among 1790 medical records reviewed, 766 (42.8%) infants had fever. Discharge diagnosis of fever demonstrated high specificity (98.2%, 95% confidence interval [CI]: 97.8-98.6) but low sensitivity (53.2%, 95% CI: 50.0-56.4). A case-identification algorithm of admission or discharge diagnosis of fever exhibited higher sensitivity (71.1%, 95% CI: 68.2-74.0), similar specificity (97.7%, 95% CI: 97.3-98.1), and the highest positive predictive value (86.9%, 95% CI: 84.5-89.3).
  
  
  CONCLUSIONS
  A case-identification strategy that includes admission or discharge diagnosis of fever should be considered for febrile infant studies using administrative data, though underclassification of patients is a potential limitation.
authors.affiliation: Department of Pediatrics, Section of Emergency Medicine, Yale School of Medicine, New Haven, Connecticut.
authors.forename: Paul L
authors.initials: PL
authors.lastname: Aronson
authors.affiliation: Division of Hospital Medicine, Department of Pediatrics, The Monroe Carell Jr Children's Hospital at Vanderbilt, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Williams
authors.affiliation: Children's Hospital Association, Overland Park, Kansas.
authors.forename: Cary
authors.initials: C
authors.lastname: Thurm
authors.affiliation: Division of Hospital Medicine, Department of Pediatrics, Seattle Children's Hospital, University of Washington School of Medicine, Seattle, Washington.
authors.forename: Joel S
authors.initials: JS
authors.lastname: Tieder
authors.affiliation: Division of Emergency Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Alpern
authors.affiliation: Division of Emergency Medicine, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Lise E
authors.initials: LE
authors.lastname: Nigrovic
authors.affiliation: Division of Hospital Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio.
authors.forename: Amanda C
authors.initials: AC
authors.lastname: Schondelmeyer
authors.affiliation: The Center for Pediatric Clinical Effectiveness and Division of Emergency Medicine, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Fran
authors.initials: F
authors.lastname: Balamuth
authors.affiliation: Division of Infectious Diseases, Department of Pediatrics, Children's Mercy Hospital, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri.
authors.forename: Angela L
authors.initials: AL
authors.lastname: Myers
authors.affiliation: Division of Infectious Diseases, Department of Pediatrics, Children's Mercy Hospital, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri.
authors.forename: Russell J
authors.initials: RJ
authors.lastname: McCulloh
authors.affiliation: James M. Anderson Center for Health Systems Excellence and Division of Emergency Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio.
authors.forename: Evaline A
authors.initials: EA
authors.lastname: Alessandrini
authors.affiliation: Division of Hospital Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio.|Division of Infectious Diseases, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio.
authors.forename: Samir S
authors.initials: SS
authors.lastname: Shah
authors.affiliation: Division of Hospital Medicine, Department of Pediatrics, The Monroe Carell Jr Children's Hospital at Vanderbilt, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Whitney L
authors.initials: WL
authors.lastname: Browning
authors.affiliation: The Center for Pediatric Clinical Effectiveness and Division of Emergency Medicine, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Katie L
authors.initials: KL
authors.lastname: Hayes
authors.affiliation: Division of Hospital Medicine, Department of Pediatrics, Seattle Children's Hospital, University of Washington School of Medicine, Seattle, Washington.
authors.forename: Elana A
authors.initials: EA
authors.lastname: Feldman
authors.affiliation: Division of Emergency Medicine, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Mark I
authors.initials: MI
authors.lastname: Neuman
mesh_terms: D003430:Cross-Sectional Studies; D016208:Databases, Factual / Q000592:standards; D005260:Female; D005334:Fever / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D038801:International Classification of Diseases / Q000592:standards*; D008297:Male; D010351:Patient Discharge / Q000592:standards*; D012189:Retrospective Studies; D013223:Statistics as Topic / Q000592:standards*