SUN-263 COMPARISON OF MORTALITY AND END-STAGE RENAL DISEASE (ESRD) AMONG RACIAL/ETHNIC GROUPS IN THE U.S. VETERAN INCIDENT CKD POPULATION

Abstract

Using an incident, rather than prevalent, chronic kidney disease (CKD) population is essential when the research purpose is to understand the difference in CKD progression and associated risk factors among racial/ethnic groups. We recently constructed a national incident CKD cohort from the United States (US) veteran population. Here, we report mortality and progression to ESRD among racial/ethnic groups. The incident CKD cohort includes all subjects who had two estimated glomerular filtration rates (eGFRs) <60 mL/min/1.73 m2 with at least 90 days apart between 1/1/2002 and 5/01/2011 in the US Veteran Affairs database. eGFRs were calculated using the CKD Epidemiology Collaboration (CKD-EPI) estimating equation. The first date of laboratory occurrences serves as the index date. Subjects were excluded if they had been in the database for <2 years prior to the index date, did not have any eGFR values of >60 during the prior two years, or had prior ESRD (transplantation or dialysis). These exclusion criteria ensure that the index date was close to the true CKD onset. All subjects were followed for a fixed length of 5 years for outcomes including pre-ESRD death, ESRD event, or death after ESRD. Percentages of events within 5 years of index date and hazard ratios were examined. Of the 498,439 subjects included, 413,963 were White, 59,082 Black, 16,946 Hispanic, 2177 American Indian or Alaska Native (AI), 1894 Asian, and 4377 Native Hawaiian or Pacific Islander (NH). These groups had similar mean eGFR levels at entry (range 52-53 ml/min/1.73m2) and gender distributions (96-97% male). Findings: 1) At CKD onset Blacks were the youngest (mean age 51.7) while Whites and Asians were the oldest (both at 53). 2) In all age groups, Asians had substantially lower percentages of pre-ESRD deaths than other race groups which had relatively similar percentages (Table). Blacks and Hispanics had greater percentages of ESRD events while Whites had substantially lower percentages of ESRD. 3) As for competing risks, all races were more likely to die than to develop ESRD, except for ages under 50 years where Asians and Blacks were more likely to develop ESRD. 4) In the pre-ESRD and ESRD periods combined, Asians had the lowest percentage of total deaths in all age groups, Hispanics had the greatest percentage of total deaths in ages under 50, and Blacks had the greatest percentage of total deaths in ages above 50. 5) The hazard ratios for other races vs. Whites were little changed with adjustment for age, baseline eGFR, and gender. TablePercentages of events within 5 years of index date by race/ethnicity and ageAge groupRace/ethnicity% pre-ESRD death% ESRD event% total deaths in both pre-ESRD and ESRD18 - 50White15.55.117.0Black14.315.117.8Hispanic16.313.220.2American Indian (AI)16.812.617.9Asian9.912.316.0Native Hawaiian or Pacific Islander (NH)16.110.317.451 - 70White18.91.819.5Black19.56.421.3Hispanic18.35.820.2AI19.34.520.5Asian9.23.29.9NH15.52.716.171 - 100White30.20.630.5Black34.41.335.1Hispanic30.01.030.4AI27.11.327.8Asian25.70.225.9NH28.80.929.2 Open table in a new tab In this incident cohort of US veterans with new onset CKD, the risks of death and developing ESRD differ by racial/ethnic groups. Research to assess biological and non-biological determinants for these differences will lead to more tailored treatment that may improve outcomes for all patients with CKD.