1. ¹Research & Evaluation, Kaiser Permanente Southern California, Pasadena, California, USA
2. ²Department of Medicine, Baldwin Park Medical Center, Kaiser Permanente Southern California, Los Angeles, California, USA
3. ³Renal Research Institute, New York, New York, USA
4. ⁴Renal Program, Kaiser Permanente Southern California, Pasadena, California, USA

Correspondence: Stephen F. Derose, Research & Evaluation, Kaiser Permanente Southern California, 100 S Los Robles, 2nd Floor, Pasadena, California, USA. E-mail: Stephen.F.Derose@kp.org

Received 15 December 2008; Revised 15 April 2009; Accepted 21 April 2009; Published online 10 June 2009.

Abstract

African Americans have the highest incidence of end-stage renal disease (ESRD) in the United States. To understand the basis of this disparity, we examined data from a prepaid, integrated health system for this retrospective cohort study of members who had one or more serum creatinine tests performed over a 9-year period. The cohort included 182,959 adults (8% black) with stage 3 or 4 chronic kidney disease based on their estimated glomerular filtration rate (eGFR). Competing-risk methods were used to determine the incidence of ESRD and death prior to ESRD. At all follow-up times and from any entry eGFR, the cumulative incidence of ESRD was significantly greater in blacks. The age and gender-adjusted hazard ratios for ESRD and death prior to ESRD in blacks compared to non-blacks were 1.83 and 1.15, respectively. Increased survival free of ESRD was found in blacks 70 years and older with eGFR stage 4. The hazard ratio for the combined outcomes of ESRD or death was 1.31 in blacks as compared to non-blacks. Despite equivalent health insurance benefits, blacks with chronic kidney disease were at increased risk for ESRD and death prior to ESRD. Compared to non-blacks, blacks with chronic kidney disease were twice as likely to enter into ESRD as to die prior to ESRD.