Survival Advantage in Black Versus White Men With CKD: Effect of Estimated GFR and Case Mix
- Author(s): Kovesdy, Csaba P.
- Quarles, L. Darryl
- Lott, Evan H.
- Lu, Jun Ling
- Ma, Jennie Z.
- Molnar, Miklos Z.
- Kalantar-Zadeh, Kamyar
- et al.
Published Web Locationhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC3644312/pdf/nihms432012.pdf
Black dialysis patients have significantly lower mortality compared to white patients, in contradistinction to the higher mortality seen in blacks in the general population. It is unclear if a similar paradox exists in non–dialysis-dependent CKD, and if it does, what its underlying reasons are.Study Design
Historical cohort.Setting & Participants
518,406 white and 52,402 black male US veterans with non-dialysis dependent CKD stages 3–5.Predictor
Black race.Outcomes & Measurements
We examined overall and CKD stage-specific all-cause mortality using parametric survival models. The effect of sociodemographic characteristics, comorbidities and laboratory characteristics on the observed differences was explored in multivariable models.Results
Over a median follow-up of 4.7 years 172,093 patients died (mortality rate, 71.0 [95% CI, 70.6–71.3] per 1000 patient-years). Black race was associated with significantly lower crude mortality (HR, 0.95; 95% CI, 0.94–0.97; p<0.001). The survival advantage was attenuated after adjustment for age (HR, 1.14; 95% CI, 1.12–1.16), but was even magnified after full multivariable adjustment (HR, 0.72; 95% CI, 0.70–0.73; p<0.001). The unadjusted survival advantage of blacks was more prominent in those with more advanced stages of CKD, but CKD stage-specific differences were attenuated by multivariable adjustment.Limitations
Exclusively male patients.Conclusions
Black patients with CKD have lower mortality compared to white patients. The survival advantage seen in blacks is accentuated in patients with more advanced stages of CKD, which may be explained by changes in case mix and laboratory characteristics occurring during the course of kidney disease.