title: Charlson comorbidity index using administrative database in incident PD patients.
abstract: OBJECTIVE
  Mortality risks in ESRD (end stage renal disease) patients are related to comorbid diseases. The Charlson Comorbidity Index (CCI) has been reported to be a strong predictor of survival in incipient ESRD patients. The authors studied the validity of CCI using administrative database according to International Classification of Disease, 10th revision (ICD-10) codes, to devise a more straightforward method of determining CCI than that based on medical records review.
  
  
  METHODS
  Incident peritoneal dialysis patients (N = 134) were enrolled from 1997 through 2007. We compared CCI scored by the administrative database (A-CCI) with CCI scored by medical records review (R-CCI). These CCI scores and patients' outcomes were analyzed.
  
  
  RESULTS
  For all patients, mean A-CCI and R-CCI were 5.3 +/- 2.1 (range 2 - 11) and 5.4 +/- 2.1 (range 2 - 11), respectively. High correlation was found between A-CCI and R-CCI scores (r = 0.88, p < 0.01). The sensitivity of A-CCI was high (0.57 - 1.00) for nine comorbidities, but sensitivities for chronic pulmonary disease and peptic ulcer disease were poor (< 0.50). However, specificity was excellent for most comorbidities. Three comorbidity groups were established by tertile ranking: low comorbidity (score = 2 - 4), moderate comorbidity (score = 5 - 6), and high comorbidity (score = 7-11). The mortality rates were; 7.17, 15.96, and 23.07/100 patient-years by A-CCI, and 6.69, 13.58 and 28.16/100 patient-years by R-CCI, respectively.
  
  
  CONCLUSIONS
  CCI scores from administrative database using ICD-10 were similar to CCI scores by medical records review. This method is simple and valid to predict the outcomes of incipient PD patients.
authors.affiliation: Division of Nephrology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: S-H
authors.initials: SH
authors.lastname: Jang
authors.forename: J-W
authors.initials: JW
authors.lastname: Chea
authors.forename: K-B
authors.initials: KB
authors.lastname: Lee
mesh_terms: D015897:Comorbidity / Q000639:trends; D003628:Database Management Systems / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000628:therapy; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000453:epidemiology*; D010530:Peritoneal Dialysis / Q000706:statistics & numerical data*; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology*; D015203:Reproducibility of Results; D012107:Research Design; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015996:Survival Rate / Q000639:trends