title: Comparison of pediatric cardiac surgical mortality rates from national administrative data to contemporary clinical standards.
abstract: BACKGROUND
  Despite the superior coding and risk adjustment of clinical data, the ready availability, national scope, and perceived unbiased nature of administrative data make it the choice of governmental agencies and insurance companies for evaluating quality and outcomes. We calculated pediatric cardiac surgery mortality rates from administrative data and compared them with widely quoted standards from clinical databases.
  
  
  METHODS
  Pediatric cardiac surgical operations were retrospectively identified by ICD-9-CM diagnosis and procedure codes from the Nationwide Inpatient Sample (NIS) 1988-2005 and the Kids' Inpatient Database (KID) 2003. Cases were grouped into Risk Adjustment for Congenital Heart Surgery, version 1 (RACHS-1) categories. In-hospital mortality rates and 95% confidence intervals were calculated.
  
  
  RESULTS
  A total of 55,164 operations from the NIS and 10,945 operations from the KID were placed into RACHS-1 categories. During the 18-year period, the overall NIS mortality rate for pediatric cardiac surgery decreased from 8.7% (95% confidence interval, 8.0% to 9.3%) to 4.6% (95% confidence interval, 4.3% to 5.0%). Mortality rates by RACHS-1 category decreased significantly as well. The KID and NIS mortality rates from comparable years were similar. Overall mortality rates derived from administrative data were higher than those from contemporary national clinical data, The Society of Thoracic Surgeons Congenital Heart Surgery Database, or published data from pediatric cardiac specialty centers. Although category-specific mortality rates were higher in administrative data than in clinical data, a minority of the relationships reached statistical significance.
  
  
  CONCLUSIONS
  Despite substantial improvement, mortality rates from administrative data remain higher than those from clinical data. The discrepancy may be attributable to several factors: differences in database design and composition, differences in data collection and reporting structures, and variation in data quality.
authors.affiliation: Division of Cardiothoracic Surgery, Oregon Health and Science University, Portland, Oregon 97239-3098, USA. welkek@ohsu.edu
authors.forename: Karl F
authors.initials: KF
authors.lastname: Welke
authors.forename: Brian S
authors.initials: BS
authors.lastname: Diggs
authors.forename: Tara
authors.initials: T
authors.lastname: Karamlou
authors.forename: Ross M
authors.initials: RM
authors.lastname: Ungerleider
mesh_terms: D017677:Age Distribution; D006348:Cardiac Surgical Procedures / Q000379:methods / Q000401:mortality*; D016507:Cardiology Service, Hospital; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D016001:Confidence Intervals; D016208:Databases, Factual; D035082:Federal Government; D005260:Female; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000401:mortality* / Q000601:surgery*; D017052:Hospital Mortality / Q000639:trends*; D006776:Hospitals, Pediatric / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007223:Infant; D038801:International Classification of Diseases; D008297:Male; D011336:Probability; D012015:Reference Standards; D012189:Retrospective Studies; D017678:Sex Distribution; D016019:Survival Analysis; D014481:United States