Table 1.
Study population characteristics by KPSC Creatinine SureNet follow-up statusa
| Characteristic | No follow-up | Follow-up | Total | p value |
|---|---|---|---|---|
| Population | 5414 (43.7) | 6980 (56.3) | 12,394 (100.0) | < 0.001 |
| Female sex | 2289 (42.3) | 3878 (55.6) | 6167 (49.8) | |
| First eGFR (mL/min/m2) | ||||
| Mean (SD) | 52.1 (7.6) | 52.1 (7.2) | 52.1 (7.3) | 0.231 |
| < 15 | 14 (0.3) | 9 (0.1) | 23 (0.2) | |
| 15 ≤ 30 | 93 (1.7) | 85 (1.2) | 178 (1.4) | |
| 30 ≤ 45 | 626 (11.6) | 817 (11.7) | 1443 (11.6) | |
| 45 ≤ 60 | 4681 (86.5) | 6069 (86.9) | 10,750 (86.7) | |
| > 60 | — | — | — | |
| Age at index date (years) | ||||
| Mean (SD) | 47.5 (12.38) | 50.9 (12.54) | 49.4 (12.58) | < 0.001 |
| 18–39 | 1299 (24) | 1152 (16.5) | 2451 (19.8) | |
| 40–64 | 3631 (67.1) | 4825 (69.1) | 8456 (68.2) | |
| 65–85 | 454 (8.4) | 939 (13.5) | 1393 (11.2) | |
| > 85 | 30 (0.6) | 64 (0.9) | 94 (0.8) | |
| Race/ethnicity | ||||
| Hispanic | 1046 (19.3) | 1272 (18.2) | 2318 (18.7) | < 0.001 |
| White, non-Hispanic | 2423 (44.8) | 3897 (55.8) | 6320 (51) | |
| Black, non-Hispanic | 645 (11.9) | 753 (10.8) | 1398 (11.3) | |
| Asian, non-Hispanic | 373 (6.9) | 509 (7.3) | 882 (7.1) | |
| Other, non-Hispanic | 927 (17.1) | 549 (7.9) | 1476 (11.9) | |
| Charlson Comorbidity Index | ||||
| 0 | 3300 (61) | 3366 (48.2) | 6666 (53.8) | < 0.001 |
| 1–2 | 1723 (31.9) | 2819 (40.4) | 4542 (36.7) | |
| ≥ 3 | 384 (7.1) | 794 (11.4) | 1178 (9.5) | |
| Comorbidities | ||||
| Hypertension | 1491 (27.5) | 2562 (36.7) | 4053 (32.7) | < 0.001 |
| Diabetes mellitus | 418 (7.7) | 679 (9.7) | 1097 (8.9) | < 0.001 |
| History of systemic lupus | 1 (0.0) | 4 (0.1) | 5 (0.0) | 0.286 |
| Stroke | 114 (2.1) | 201 (2.9) | 315 (2.5) | 0.007 |
| Congestive heart failure | 76 (1.4) | 66 (0.9) | 142 (1.1) | 0.017 |
| Outcomes | ||||
| All-cause mortality | 142 (2.6) | 159 (2.3) | 301 (2.4) | 0.216 |
| End-stage renal disease | 27 (0.5) | 56 (0.8) | 83 (0.7) | 0.04 |
| Length of follow-up (years)b | ||||
| Mean (SD) | 4.2 (2.99) | 4.1 (2.22) | 4.2 (2.59) | < 0.001 |
| Median (IQR) | 3.5 (2.1–5.4) | 3.8 (2.64.9) | 3.7 (2.4–5.1) | |
| Range | 0–18.9 | 0.3–18.7 | 0–18.9 | |
a
Data are presented as no. (%) unless indicated otherwise.
b
Follow-up was estimated from the date of first creatinine measurement through the earliest of 1) death, 2) end of KPSC membership, 3) December 31, 2015, or 4) date of diagnosis of end-stage renal disease.
eGFR = estimated glomerular filtration rate; IQR = interquartile range; KPSC = Kaiser Permanente Southern California; SD = standard deviation.