Table 1.
Characteristics of the Participants in the Development and Validation Data Sets.*
| Characteristic | eGFRcr 2009 Development Data Set | eGFRcr-cys 2012 Development Data Set | 2021 Validation Data Set | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Overall (N = 8254) |
Black (N = 2601) |
Non-Black (N = 5653) |
Overall (N = 5352) |
Black (N = 2123) |
Non-Black (N = 3229) |
Overall (N = 4050) |
Black (N = 579) |
Non-Black (N = 3471) |
|
| Percent of overall population | 100 | 31.5 | 68.5 | 100 | 39.7 | 60.3 | 100 | 14.3 | 85.7 |
| Age — yr | 47.0±14.8 | 52.8±12.0 | 44.3±15.2 | 46.5±15.1 | 53.1±11.6 | 42.2±15.6 | 57.0±17.4 | 53.6±12.6 | 57.6±18.0 |
| Age category — no. (%) | |||||||||
| <40 yr | 2921 (35.4) | 397 (15.3) | 2524 (44.6) | 2008 (37.5) | 299 (14.1) | 1709 (52.9) | 715 (17.7) | 59 (10.2) | 656 (18.9) |
| 40–65 yr | 4309 (52.2) | 1807 (69.5) | 2502 (44.3) | 2625 (49.0) | 1463 (68.9) | 1162 (36.0) | 1989 (49.1) | 417 (72.0) | 1572 (45.3) |
| >65 yr | 1024 (12.4) | 397 (15.3) | 627 (11.1) | 719 (13.4) | 361 (17.0) | 358 (11.1) | 1346 (33.2) | 103 (17.8) | 1243 (35.8) |
| Female sex — no. (%) | 3606 (43.7) | 1026 (39.4) | 2580 (45.6) | 2245 (41.9) | 822 (38.7) | 1423 (44.1) | 1557 (38.4) | 140 (24.2) | 1417 (40.8) |
| BMI† | 28.2±6.1 | 30.6±6.7 | 27.2±5.5 | 28.3±6.3 | 30.8±6.9 | 26.6±5.2 | 26.9±5.0 | 28.0±6.0 | 26.8±4.8 |
| BMI category — no. (%)† | |||||||||
| <20 | 285 (3.5) | 60 (2.3) | 225 (4.0) | 214 (4.0) | 53 (2.5) | 161 (5.0) | 165 (4.1) | 23 (4.0) | 142 (4.1) |
| 20 to <25 | 2446 (29.6) | 457 (17.6) | 1989 (35.2) | 1585 (29.6) | 360 (17.0) | 1225 (37.9) | 1366 (33.8) | 173 (29.9) | 1193 (34.4) |
| 25 to <30 | 2923 (35.4) | 862 (33.1) | 2061 (36.5) | 1881 (35.2) | 686 (32.3) | 1195 (37.0) | 1623 (40.1) | 215 (37.2) | 1408 (40.6) |
| ≥30 | 2600 (31.5) | 1222 (47.0) | 1378 (24.4) | 1671 (31.2) | 1024 (48.2) | 647 (20.0) | 890 (22.0) | 167 (28.9) | 723 (20.9) |
| Diabetes — no. (%)‡ | 2406 (29.1) | 297 (11.4) | 2109 (37.3) | 1726 (32.2) | 199 (9.4) | 1527 (47.3) | 1357 (37.5) | 171 (33.4) | 1186 (38.2) |
| Kidney-donor candidates — no. (%) | 1030 (12.5) | 69 (2.7) | 961 (17.0) | 180 (3.4) | 10 (0.5) | 170 (5.3) | 459 (11.3) | 14 (2.4) | 445 (12.8) |
| Measured GFR — ml/min/1.73 m2 | 67.6±39.6 | 55.5±27.2 | 73.2±43.0 | 67.9±38.6 | 56.5±25.4 | 75.4±43.6 | 76.4±29.6 | 84.0±26.0 | 75.1±30.0 |
| Measured GFR category — no. (%) | |||||||||
| <30 ml/min/1.73 m2 | 1722 (20.9) | 513 (19.7) | 1209 (21.4) | 945 (17.7) | 331 (15.6) | 614 (19.0) | 254 (6.3) | 14 (2.4) | 240 (6.9) |
| 30 to <60 ml/min/1.73 m2 | 2334 (28.3) | 1026 (39.4) | 1308 (23.1) | 1765 (33.0) | 913 (43.0) | 852 (26.4) | 896 (22.1) | 84 (14.5) | 812 (23.4) |
| 60 to <90 ml/min/1.73 m2 | 1669 (20.2) | 793 (30.5) | 876 (15.5) | 1105 (20.6) | 679 (32.0) | 426 (13.2) | 1601 (39.5) | 240 (41.5) | 1361 (39.2) |
| ≥90 ml/min/1.73 m2 | 2529 (30.6) | 269 (10.3) | 2260 (40.0) | 1537 (28.7) | 200 (9.4) | 1337 (41.4) | 1299 (32.1) | 241 (41.6) | 1058 (30.5) |
| Creatinine — mg/dl | 1.66±1.16 | 1.86±1.09 | 1.56±1.18 | 1.57±0.93 | 1.74±0.85 | 1.45±0.97 | 1.16±0.70 | 1.16±0.56 | 1.16±0.72 |
| Cystatin C — mg/liter | NA | NA | NA | 1.43±0.71 | 1.49±0.63 | 1.39±0.76 | 1.18±0.55 | 1.05±0.41 | 1.20±0.57 |
Plus–minus values are means ±SD. Race was reported by the participants. To convert the values for glomerular filtration rate (GFR) to milliliters per second per square meter, multiply by 0.0167. To convert the values for serum creatinine to micromoles per liter, multiply by 88.4. Percentages may not total 100 because of rounding. Descriptive data according to the studies used for each data set are provided in Tables S6 through S8 in the Supplementary Appendix. The term eGFRcr denotes estimated GFR from creatinine equation, eGFRcr-cys estimated GFR from creatinine–cystatin C equation, and NA not applicable.
In the 2012 development data set, data on body-mass index (BMI) were available for 5351 participants in the overall population, 2123 Black participants, and 3228 non-Black participants. In the 2021 validation data set, data on BMI were available for 4044 participants in the overall population, 578 Black participants, and 3466 non-Black participants.
In the 2021 validation data set, data on diabetes status were available for 3616 participants in the overall population, 512 Black participants, and 3104 non-Black participants.