title: Charlson comorbidity score is a strong predictor of mortality in hemodialysis patients.
abstract: OBJECTIVE
  The Charlson comorbidity index (CCI) is a commonly used scale for assessing morbidity, but its role in assessing mortality in hemodialysis patients is not clear. Age, a component of CCI, is a strong risk factor for morbidity and mortality in chronic diseases and correlates with comorbidities. We hypothesized that the Charlson comorbidity index without age is a strong predictor of mortality in hemodialysis patients.
  
  
  METHODS
  A 6-year cohort of 893 hemodialysis patients was examined for an association between a modified CCI (without age and kidney disease) (mCCI) and mortality.
  
  
  RESULTS
  Patients were 53±15 years old (mean±SD), had a median mCCI score of 2, and included 47% women, 31% African Americans and 55% diabetics. After adjusting for case-mix and nutritional and inflammatory markers including C-reactive protein and interleukin-6, 2nd (mCCI: 1-2), 3rd (mCCI=3), and 4th (mCCI: 4-9) quartiles compared to 1st (mCCI=0) quartiles showed death hazard ratios (95% confidence intervals) of 1.43 (0.92-2.23), 1.70 (1.06-2.72), and 2.33 (1.43-3.78), respectively. The mCCI-death association was robust in non-African Americans. The CCI-death association linearity was verified in cubic splines. Each 1 unit higher mCCI score was associated with a death hazard ratio of 1.16 (1.07-1.27).
  
  
  CONCLUSIONS
  CCI independent of age is a robust and linear predictor of mortality in hemodialysis patients, in particular in non-African Americans.
authors.affiliation: Harold Simmons Center for Chronic Disease Research and Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, 1124 West Carson Street, C1-Annex, Torrance, CA 90502, USA.
authors.forename: Manoch
authors.initials: M
authors.lastname: Rattanasompattikul
authors.forename: Usama
authors.initials: U
authors.lastname: Feroze
authors.forename: Miklos Z
authors.initials: MZ
authors.lastname: Molnar
authors.forename: Ramanath
authors.initials: R
authors.lastname: Dukkipati
authors.forename: Csaba P
authors.initials: CP
authors.lastname: Kovesdy
authors.forename: Allen R
authors.initials: AR
authors.lastname: Nissenson
authors.forename: Keith C
authors.initials: KC
authors.lastname: Norris
authors.forename: Joel D
authors.initials: JD
authors.lastname: Kopple
authors.forename: Kamyar
authors.initials: K
authors.lastname: Kalantar-Zadeh
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D006435:Renal Dialysis / Q000401:mortality*