title: Comorbidity ascertainment from the ESRD Medical Evidence Report and Medicare claims around dialysis initiation: a comparison using US Renal Data System data.
abstract: BACKGROUND
  The end-stage renal disease Medical Evidence Report serves as a source of comorbid condition data for risk adjustment of quality metrics. We sought to compare comorbid condition data in the Medical Evidence Report around dialysis therapy initiation with diagnosis codes in Medicare claims.
  
  
  METHODS
  Observational cohort study using US Renal Data System data.
  
  
  METHODS
  Medicare-enrolled elderly (≥66 years) patients who initiated maintenance dialysis therapy July 1 to December 31, 2007, 2008, or 2009.
  
  
  METHODS
  12 comorbid conditions ascertained from claims during the 6 months before dialysis therapy initiation, the Medical Evidence Report, and claims during the 3 months after dialysis therapy initiation.
  
  
  METHODS
  None.
  
  
  RESULTS
  Comorbid condition prevalence according to claims before dialysis therapy initiation generally exceeded prevalence according to the Medical Evidence Report. The κ statistics for comorbid condition designations other than diabetes ranged from 0.06 to 0.43. Discordance of designations was associated with age, race, sex, and end-stage renal disease Network. During 23,930 patient-years of follow-up from 4 to 12 months after dialysis therapy initiation (8,930 deaths), designations from claims during the 3 months after initiation better discriminated risk of death than designations from the Medical Evidence Report (C statistics of 0.674 vs 0.616). Between the Medical Evidence Report and claims, standardized mortality ratios changed by >10% for more than half the dialysis facilities.
  
  
  CONCLUSIONS
  Neither the Medical Evidence Report nor diagnosis codes in claims constitute a gold standard of comorbid condition data; results may not apply to nonelderly patients or patients without Medicare coverage.
  
  
  CONCLUSIONS
  Discordance of comorbid condition designations from the Medical Evidence Report and claims around dialysis therapy initiation was substantial and significantly associated with patient characteristics, including location. These patterns may engender bias in risk-adjusted quality metrics. In lieu of the Medical Evidence Report, claims during the 3 months after dialysis therapy initiation may constitute a useful source of comorbid condition data.
authors.affiliation: DaVita Clinical Research, DaVita HealthCare Partners Inc, Denver, CO.
authors.forename: Mahesh
authors.initials: M
authors.lastname: Krishnan
authors.affiliation: Chronic Disease Research Group, Minneapolis Medical Research Foundation, Minneapolis, MN. Electronic address: eweinhandl@cdrg.org.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Weinhandl
authors.affiliation: Chronic Disease Research Group, Minneapolis Medical Research Foundation, Minneapolis, MN.
authors.forename: Scott
authors.initials: S
authors.lastname: Jackson
authors.affiliation: Chronic Disease Research Group, Minneapolis Medical Research Foundation, Minneapolis, MN.
authors.forename: David T
authors.initials: DT
authors.lastname: Gilbertson
authors.affiliation: Clinical Science, Epidemiology, and Research, Fresenius Medical Care, North America, Waltham, MA.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Lacson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000437:Alcoholism / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D015897:Comorbidity; D003324:Coronary Artery Disease / Q000453:epidemiology; D003625:Data Collection; D016208:Databases, Factual; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000628:therapy; D008297:Male; D006278:Medicare; D051346:Mobility Limitation; D009369:Neoplasms / Q000453:epidemiology*; D016491:Peripheral Vascular Diseases / Q000453:epidemiology; D016016:Proportional Hazards Models; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology*; D006435:Renal Dialysis; D012189:Retrospective Studies; D019966:Substance-Related Disorders / Q000453:epidemiology*; D014029:Tobacco Use Disorder / Q000453:epidemiology; D014481:United States / Q000453:epidemiology
keywords: CMS 2728; CMS quality metrics; Medical Evidence Report; Medicare claims; US Renal Data System (USRDS); comorbid conditions; comorbidity ascertainment; data discordance; diagnosis codes; dialysis information systems; dialysis initiation; end-stage renal disease (ESRD); misclassification; renal replacement therapy (RRT)