Table 2.
Comparison of baseline patient characteristics by attendance status: pre-match
| Variables | Overall, N = 93,389 | Attended, N = 92,107 | Absence, N = 1282 | Standardized difference (%) | P-value |
|---|---|---|---|---|---|
| Age (years) | <0.001 | ||||
| Mean ± SD | 62.9 ± 14.5 | 62.9 ± 14.5 | 60.5 ± 14.5 | −16.9 | |
| Gender, n (%) | 0.33 | ||||
| Female | 41,424 (44.4) | 40,838 (44.3) | 586 (45.7) | 2.8 | |
| Race, n (%) | <0.001 | ||||
| White | 35,425 (37.9) | 34,982 (38.0) | 443 (34.6) | −7.1 | |
| Black | 36,310 (38.9) | 35,720 (38.8) | 590 (46.0) | 14.7 | |
| Hispanic | 14,843 (15.9) | 14,653 (15.9) | 190 (14.8) | −3.0 | |
| Asian | 3043 (3.3) | 3028 (3.3) | 15 (1.2) | −14.4 | |
| Other/unknown | 3768 (4.0) | 3724 (4.0) | 44 (3.4) | −3.2 | |
| Vascular access, n (%) | 0.05 | ||||
| Arteriovenous fistula | 63,831 (68.3) | 63,000 (68.4) | 831 (64.8) | −7.6 | |
| Arteriovenous graft | 20,999 (22.5) | 20,685 (22.5) | 314 (24.5) | 4.8 | |
| Central venous catheter | 8556 (9.2) | 8419 (9.1) | 137 (10.7) | 5.2 | |
| Other/missing | 3 (0.0) | 3 (0.0) | 0 (0.0) | ||
| Dialysis vintage (months) | 0.006 | ||||
| Median [p25, p75] | 48 [26, 81] | 48 [26, 81] | 45 [24, 76] | −10.5 | |
| Target weight (kg) | 0.34 | ||||
| Mean ± SD | 80.7 ± 22.5 | 80.7 ± 22.5 | 81.3 ± 22.2 | 2.7 | |
| Etiology of ESRD, n (%) | 0.12 | ||||
| Diabetes | 41,917 (44.9) | 41,323 (44.9) | 594 (46.3) | 3.0 | |
| Hypertension | 28,576 (30.6) | 28,171 (30.6) | 405 (31.6) | 2.2 | |
| Other | 22,896 (24.5) | 22,613 (24.6) | 283 (22.1) | −5.9 | |
| Atrial fibrillation, n (%) | 105 (0.1) | 104 (0.1) | <10 | −1.1 | 0.71 |
| Diabetes, n (%) | 63,728 (68.2) | 62,804 (68.2) | 924 (72.1) | 8.5 | 0.003 |
| Congestive heart failure, n (%) | 13,507 (14.5) | 13,306 (14.4) | 201 (15.7) | 3.4 | 0.21 |
| Coronary artery disease, n (%) | 11,586 (12.4) | 11,438 (12.4) | 148 (11.5) | −2.7 | 0.35 |
| Cerebrovascular disease, n (%) | 968 (1.0) | 956 (1.0) | 12 (0.9) | −1.0 | 0.72 |
| Peripheral vascular disease, n (%) | 7588 (8.1) | 7487 (8.1) | 101 (7.9) | −0.9 | 0.74 |
| Serum albumin (g/dL) | 0.004 | ||||
| Mean ± SD | 4.0 ± 0.4 | 4.0 ± 0.4 | 3.9 ± 0.4 | −8.0 | |
| Serum calcium (mg/dL) | 0.69 | ||||
| Mean ± SD | 9.0 ± 0.7 | 9.0 ± 0.7 | 9.0 ± 0.7 | −1.1 | |
| Creatinine (mg/dL) | 0.31 | ||||
| Mean ± SD | 8.7 ± 2.9 | 8.7 ± 2.9 | 8.6 ± 2.9 | −3.0 | |
| Ferritin (ng/mL) | 0.73 | ||||
| Mean ± SD | 759.9 ± 351.8 | 759.9 ± 351.6 | 763.3 ± 366.2 | 1.0 | |
| Hemoglobin (g/dL) | 0.41 | ||||
| Mean ± SD | 10.9 ± 1.1 | 10.9 ± 1.1 | 10.9 ± 1.1 | −2.3 | |
| Serum phosphate (mg/dL) | <0.001 | ||||
| Mean ± SD | 4.98 ± 1.39 | 4.98 ± 1.39 | 5.11 ± 1.43 | 9.5 | |
| Parathyroid hormone (ng/mL) | 0.23 | ||||
| Median [p25, p75] | 335 [220, 500] | 334 [220, 499] | 338 [227, 522] | 3.9 | |
| Transferrin saturation (%) | 0.67 | ||||
| Mean ± SD | 31.2 ± 12.3 | 31.2 ± 12.3 | 31.0 ± 12.4 | −1.2 | |
| nPCR (g/kg/day) | <0.001 | ||||
| Mean ± SD | 1.04 ± 0.28 | 1.04 ± 0.28 | 1.00 ± 0.28 | −14.4 | |
| Kt/V | <0.001 | ||||
| Mean ± SD | 1.64 ± 0.27 | 1.64 ± 0.27 | 1.61 ± 0.28 | −13.9 |
Abbreviations: ESRD, end-stage renal disease; K, dialyzer clearance of urea; t, dialysis time; V, volume of distribution of urea; nPCR, normalized protein catabolic rate; p25, 25th percentile; p75, 75th percentile; SD, standard deviation.