title: Accuracy of the all patient refined diagnosis related groups classification system in congenital heart surgery.
abstract: BACKGROUND
  Administrative data are increasingly used to evaluate clinical outcomes and quality of care in pediatric congenital heart surgery (CHS) programs. Several published analyses of large pediatric administrative data sets have relied on the All Patient Refined Diagnosis Related Groups (APR-DRG, version 24) diagnostic classification system. The accuracy of this classification system for patients undergoing CHS is unclear.
  
  
  METHODS
  We performed a retrospective cohort study of all 14,098 patients 0 to 5 years of age undergoing any of six selected congenital heart operations, ranging in complexity from isolated closure of a ventricular septal defect to single-ventricle palliation, at 40 tertiary-care pediatric centers in the Pediatric Health Information Systems database between 2007 and 2010. Assigned APR-DRGs (cardiac versus noncardiac) were compared using χ2 or Fisher's exact tests between those patients admitted during the first day of life versus later and between those receiving extracorporeal membrane oxygenation support versus those not. Recursive partitioning was used to assess the greatest determinants of APR-DRG type in the model.
  
  
  RESULTS
  Every patient admitted on day 1 of life was assigned to a noncardiac APR-DRG (p<0.001 for each procedure). Similarly, use of extracorporeal membrane oxygenation was highly associated with misclassification of CHS patients into a noncardiac APR-DRG (p<0.001 for each procedure). Cases misclassified into a noncardiac APR-DRG experienced a significantly increased mortality (p<0.001).
  
  
  CONCLUSIONS
  In classifying patients undergoing CHS, APR-DRG coding has systematic misclassifications, which may result in inaccurate reporting of CHS case volumes and mortality.
authors.affiliation: Department of Pediatrics, Children's Healthcare of Mississippi, University of Mississippi School of Medicine, Jackson, Mississippi. Electronic address: aparnell@umc.edu.
authors.forename: Aimee S
authors.initials: AS
authors.lastname: Parnell
authors.affiliation: Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Justine
authors.initials: J
authors.lastname: Shults
authors.affiliation: Department of Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: J William
authors.initials: JW
authors.lastname: Gaynor
authors.affiliation: Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Mary B
authors.initials: MB
authors.lastname: Leonard
authors.affiliation: Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Dingwei
authors.initials: D
authors.lastname: Dai
authors.affiliation: Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Chris
authors.initials: C
authors.lastname: Feudtner
mesh_terms: D006348:Cardiac Surgical Procedures; D002675:Child, Preschool; D015331:Cohort Studies; D003953:Diagnosis-Related Groups; D005260:Female; D006330:Heart Defects, Congenital / Q000145:classification* / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: 20; 21; 4; APR-DRG; All Patient Refined Diagnosis Related Groups; CHS; D-TGA; DOL1; ECMO; HLHS; ICD-9-CM; PHIS; Pediatric Hospital Information Systems; TOF; VSD; congenital heart surgery; d-transposition of the great arteries, with or without VSD; day of life 1 admission; extracorporeal membrane support oxygenation; hypoplastic left heart syndrome; tetralogy of Fallot; using International Classification of Diseases, 9th Revision, Clinical Modification; ventricular septal defect