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. Author manuscript; available in PMC: 2014 Aug 1.
Published in final edited form as: Am J Kidney Dis. 2013 Mar 15;62(2):236–244. doi: 10.1053/j.ajkd.2013.01.019

Table 2.

Characteristics of study participants by race and ethnicity.

Characteristic Black White Hispanic Asian
No. 136,923 526,498 350,919 105,476
Age1
 Mean (y) 53 ± 15 58 ± 15 48 ± 15 53 ± 14
 Median (y) 53 [42–64] 58 [48–69] 48 [38–58] 53 [44–62]
Female sex 85,999 (62.8) 289,077 (54.9) 208,330 (59.4) 61,617 (58.4)
No. of serum creatinine tests
 Mean 10 ± 8 10 ± 7 8 ± 6 9 ± 7
 Median 8 [5–12] 7 [5–12] 6 [5–10] 7 [5–11]
Observation period2
 Mean (y) 5.0 ± 1.7 4.9 ± 1.7 4.7 ± 1.7 5.0 ± 1.6
 Median (y) 5.5 [3.9–6.4] 5.4 [3.7–6.3] 5.1 [3.5–6.2] 5.5 [3.8–6.4]
Duration of Enrollment3
 Mean (y) 10.1 ± 9.0 8.6 ± 7.9 6.1 ± 6.7 7.1 ± 7.1
 Median (y) 8.0 [2.9–14.7] 7.2 [2.7–11.9] 4.3 [0.9–8.9] 5.6 [1.2–10.4]
Disenrolled before end of study period* 16,848 (12.3) 64,103 (12.2) 59,606 (17.0) 11,074 (10.5)
Entry eGFR
 15–29 mL/min/1.73 m2 1,397 (1.02) 5,520 (1.05) 1,958 (0.56) 613 (0.58)
 30–44 mL/min/1.73 m2 3,998 (2.92) 20,732 (3.94) 5,172 (1.47) 2,041 (1,94)
 45–59 mL/min/1.73 m2 10,108 (7.38) 55,528 (10.55) 13,255 (3.78) 5,439 (5.16)
 60–74 mL/min/1.73 m2 21,240 (15.51) 113,132 (21.49) 34,127 (9.73) 13,300 (12.61)
 75–89 mL/min/1.73 m2 31,321 (22.87) 145,521 (27.64) 67,973 (19.37) 23,862 (22.62)
 ≥90 mL/min/1.73 m2 68,859 (50.29) 186,065 (35.34) 228,434 (65.10) 60,222 (57.09)
Last eGFR
 <15 mL/min/1.73 m2 1,637 (1.20) 3,288 (0.62) 2,189 (0.62) 696 (0.66)
 15–29 mL/min/1.73 m2 2,640 (1.93) 11,535 (2.19) 3,720 (1.06) 1,278 (1.21)
 30–44 mL/min/1.73 m2 5,710 (4.17) 32,319 (6.14) 8,411 (2.40) 3,423 (3.25)
 45–59 mL/min/1.73 m2 12,505 (9.13) 73,758 (14.01) 19,957 (5.69) 8,317 (7.89)
 60–74 mL/min/1.73 m2 24,442 (17.85) 126,888 (24.10) 43,952 (12.52) 18,009 (17.07)
 75–89 mL/min/1.73 m2 31,493 (23.00) 138,056 (26.22) 75,319 (21.46) 26,317 (24.95)
 ≥90 mL/min/1.73 m2 58,496 (42.72) 140,654 (26.72) 197,371 (56.24) 47,437 (44.97)
Annual change in eGFR (%) −4.0 [−16.8 to 7.7] −4.1 [−17.0 to 3.5] −4.3 [−16.0 to 0.5] −3.7 [−14.5 to 2.2]
eGFR (mL/min/1.73 m2 per y) slope5 distribution
 1st percentile −23.6 −20.1 −20.9 −17.6
 5th percentile −9.9 −8.5 −8.8 −7.8
 10th percentile −6.6 −5.8 −5.9 −5.5
 25th percentile −3.4 −3.1 −3.1 −3.1
 50th percentile −1.1 −1.1 −1.1 −1.3
 75th percentile 0.9 0.5 0.5 0.1
 90th percentile 3.7 2.9 3.1 2.3
 95th percentile 6.6 5.3 5.8 4.5
 99th percentile 18.5 14.9 15.9 12.5

Note: Characteristics were compared using the chi-square test (gender) and the Kruskal-Wallis test (all variables except gender and eGFR strata) and the Kolmogorov-Smirnov test (eGFR strata and slopes). All comparisons showed differences between one or more race/ethnic groups (P<0.001). Unless otherwise indicated, values for categorical variables are given as number (percentage); values for continuous variables, as or mean +/− SD or median [IQR].

1

Age of the study cohort was defined at the time of the first available serum creatinine test during study period.

2

Observation time = event date - first serum creatinine date.

3

Enrollment time prior to study entry.

5

Ordinary least squares regression line slope calculated for each individual in separate regressions. Perccntiles within group are given.

*

Without experiencing end-stage renal disease or death.

SD, standard deviation; IQR, interquartile range; eGFR, estimated glomerular filtration rate