Purpose
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.