Table 1.
Baseline Characteristics of Patients with Lupus Nephritis ESRD in the U.S., 1995-2008
| Total N= 12,533 |
Whites n=5,547 |
African Americans n=6,181 |
Asians n=683 |
Native- Americans n=122 |
p- value* |
Non- Hispanics n=10,502 |
Hispanics n=2,031 |
p-value* | |
|---|---|---|---|---|---|---|---|---|---|
| Demographics | |||||||||
| Female | 10,228 (81.6 %) | 4,334 (78.1%) | 5,228 (84.6%) | 569 (83.3%) | 97 (79.5%) | <0.0001 | 8,565 (81.6%) | 1,663 (82%) | 0.72 |
| Mean age at ESRD onset | 40.78 ± 14.91 | 43.29 ± 16.23 | 39.03 ± 13.41 | 36.58 ± 13.34 | 39.01 ± 13.99 | <0.0001 | 41.64 ± 15.04 | 36.37 ± 13.37 | <0.0001 |
| Laboratory measures | |||||||||
| Hemoglobin (g/dl) | 9.40 ± 1.82 | 9.64 ± 1.82 | 9.14 ± 1.77 | 9.65 ± 1.89 | 9.44 ± 2.00 | <0.0001 | 9.40 ± 1.81 | 9.37 ± 1.86 | 0.54 |
| eGFR (ml/min/1.73m2) (N=12,454) | 8.12 ± 4.89 | 8.74 ± 5.09 | 7.49 ± 4.65 | 8.75 ± 4.85 | 8.50 ± 4.34 | <0.0001 | 8.01 ± 4.76 | 8.69 ± 5.51 | <0.0001 |
| Serum albumin (g/dl) (N=10,123) | 2.92 ± 0.80 | 3.03 ± 0.78 | 2.82 ± 0.80 | 2.91 ± 0.85 | 2.81 ± 0.85 | <0.0001 | 2.92 ± 0.80 | 2.92 ± 0.81 | 0.87 |
| Mean BMI (kg/m2) (N=12,012) | 26.12 ± 6.99 | 25.70 ± 6.66 | 26.77 ± 7.32 | 23.49 ± 5.56 | 26.39 ± 6.70 | <0.0001 | 26.16 ± 7.07 | 25.91 ± 6.52 | 0.15 |
| Comorbidities | |||||||||
| Hypertension | 9,642 (77.0%) | 4,136 (74.5%) | 4,902 (79.3%) | 504 (73.8%) | 100 (82.0%) | <0.0001 | 8,130 (77.4%) | 1,512 (74.4%) | 0.004 |
| Current Smoking | 495 (4.0%) | 269 (4.8%) | 207 (3.3%) | 13 (2.0%) | - | <0.0001 | 459 (4.3%) | 36 (1.7%) | <0.0001 |
| Diabetes Mellitus | 1,123 (9.0%) | 460 (8.2%) | 614 (9.9%) | 36 (5.2%) | 13 (10.6%) | <0.0001 | 959 (9.1%) | 164 (8.0%) | 0.12 |
| Heart Failure | 1,958 (16.0%) | 889 (16.0%) | 970 (15.7%) | 73 (10.7%) | 26 (21.0%) | 0.001 | 1,709 (16.2%) | 249 (12.2%) | <0.0001 |
| Coronary Artery Disease | 845 (7.0%) | 518 (9.3%) | 302 (4.9%) | 16 (2.3%) | - | <0.0001 | 758 (7.2%) | 87 (4.2%) | <0.0001 |
| Cerebrovascular Accident | 649 (5%) | 338 (6.0%) | 284 (4.6%) | 19 (2.8%) | - | <0.0001 | 565 (5.3%) | 84 (4.1%) | 0.02 |
| Peripheral Vascular Disease | 417 (3.0%) | 226 (4.0%) | 173 (2.8%) | - | - | <0.0001 | 361 (3.4%) | 56 (2.7%) | 0.11 |
| Chronic | 295 | 188 | 101 | - | - | <0.000 | 269 | 26 | 0.0005 |
| Obstructive Pulmonary Disease | (2.0%) | (3.4%) | (1.6%) | 1 | (2.5%) | (1.3%) | |||
| Cancer | 189 (1.5%) | 119 (2.1%) | 64 (1.0%) | - | - | <0.0001 | 173 (1.6%) | 16 (0.8%) | 0.004 |
| Medical Insurance | |||||||||
| No Insurance | 1,315 (10.5%) | 531 (9.6%) | 718 (11.6%) | 60 (8.8%) | - | 0.0002 | 987 (9.4%) | 328 (16.1%) | <0.0001 |
| Medicare | 2,057 (16.4%) | 1,175 (21.0%) | 801 (13.0%) | 66 (9.6%) | 15 (12.0%) | <0.0001 | 1,878 (17.8%) | 179 (8.8%) | <0.0001 |
| Medicaid | 4,014 (32.0%) | 1,390 (25.0%) | 2,397 (38.8%) | 172 (25.0%) | 55 (45.0%) | <0.0001 | 3270 (31.1%) | 744 (36.6%) | <0.0001 |
| Private | 3,704 (29.5%) | 1,736 (31.0%) | 1,678 (27.0%) | 254 (37.0%) | 36 (29.0%) | <0.0001 | 3,187 (30.3%) | 517 (25.4%) | <0.0001 |
| Other | 1,443 (11.5%) | 715 (12.9%) | 587 (9.4%) | 131 (19.2%) | - | <0.0001 | 1,180 (11.1%) | 263 (12.9%) | 0.02 |
| Region of Residence | |||||||||
| Northeast | 2,094 (16.7%) | 1,016 (18.3%) | 978 (15.8%) | 93 (13.6%) | - | <0.0001 | 1,801 (17.2%) | 293 (14.4%) | 0.002 |
| West | 2,408 (19.2%) | 1,481 (26.7%) | 492 (8.0%) | 395 (57.8%) | 40 (32.8%) | <0.0001 | 1,642 (15.6%) | 766 (37.7%) | <0.0001 |
| South | 5,460 (43.6%) | 1,814 (32.7%) | 3,501 (56.6%) | 110 (16.1%) | 35 (28.7%) | <0.0001 | 4755 (45.3%) | 705 (34.7%) | <0.0001 |
| Midwest | 2,435 (19.4%) | 1,139 (20.5%) | 1,190 (19.3%) | 67 (9.8%) | 39 (32.0%) | <0.0001 | 2,277 (21.7%) | 158 (7.8%) | <0.0001 |
| Other Territories | 136 (1.1%) | 97 (1.8%) | 20 (0.3%) | 18 (2.6%) | - | <0.0001 | 27 (0.3%) | 109 (5.4%) | <0.0001 |
| Area-level Socioeconomic Status (SES)** | |||||||||
| Lowest Quartile of SES in USRDS | 25% | 24.3% | 27.3% | 5.2% | 49.6% | <0.0001 | 27.2% | 13.2% | <0.0001 |
| Initial ESRD Modality #x00A5; | |||||||||
| Hemodialysis | 10,099 (80.6%) | 4,235 (76.3%) | 5,264 (85.0%) | 505 (74.0%) | 95 (78.0%) | <0.0001 | 8,449 (80.4%) | 1,650 (81.2%) | 0.41 |
| Peritoneal dialysis | 1,376 (11.0%) | 692 (12.5%) | 568 (9.1%) | 102 (15.0%) | 14 (11.0%) | <0.0001 | 1,145 (10.9%) | 231 (11.4%) | 0.53 |
| Pre-emptive transplant | 337 (2.7%) | 252 (4.5%) | 46 (0.7%) | 32 (4.7%) | - | <0.0001 | 293 (2.8%) | 44 (2.2%) | 0.11 |
*
Chi-squared tests for categorical values and t- tests for continuous variables. With Bonferroni correction for multiple comparisons, threshold for statistical significance= 0.025.
**
Area-level socioeconomic status: composite index of seven zip code level indicators from 2000 U.S. Census data (Ward MM, Am J Kidney Dis, 2008)
Cell sizes < 11 suppressed per Federal research regulations
#x00A5: 5.7% of patients were classified as uncertain for the initial renal replacement modality in the Medical Evidence Report at USRDS entry.