TABLE 2.
Univariable Comparison of Patient Characteristics Between High- and Lower-Volume Centers
| Variable | n | Overall (N = 593) |
High-Volume (n = 412) |
Lower-Volume (n = 181) |
P Valuea |
|---|---|---|---|---|---|
| Age at listing, y | 593 | 49 (37-57) | 49 (37-57) | 51 (37-57) | .39 |
| Diagnosis group | 593 | .54 | |||
| Obstructive | 12 (2.0) | 10 (2.4) | 2 (1.1) | ||
| Pulmonary hypertension | 43 (7.3) | 27 (6.6) | 16 (8.8) | ||
| Restrictive | 488 (82) | 339 (82) | 149 (82) | ||
| Suppurative | 50 (8.4) | 36 (8.7) | 14 (7.7) | ||
| Sex | 593 | .57 | |||
| Female | 223 (38) | 158 (38) | 65 (36) | ||
| Male | 370 (62) | 254 (62) | 116 (64) | ||
| Blood type | 593 | .54 | |||
| A | 192 (32) | 138 (33) | 54 (30) | ||
| AB | 29 (4.9) | 17 (4.1) | 12 (6.6) | ||
| B | 74 (12) | 51 (12) | 23 (13) | ||
| O | 298 (50) | 206 (50) | 92 (51) | ||
| Prostaglandin infusions at listing | 593 | 14 (2.4) | 10 (2.4) | 4 (2.2) | >.99 |
| Resistant infection | 569 | 29 (5.1) | 21 (5.2) | 8 (4.9) | .88 |
| Diabetes | 591 | 165 (28) | 120 (29) | 45 (25) | .27 |
| Ventilator at listing | 593 | 322 (54) | 248 (60) | 74 (41) | <.001 |
| Body mass index, kg/m2 | 592 | 26.5 (22.9-29.8) | 26.4 (22.9-29.6) | 26.6 (23.0-29.9) | .52 |
| Pulmonary arterial mean pressure, mmHg | 391 | 29 (23-40) | 30 (23-40) | 29 (22-41) | .75 |
| Cardiac output, L/min | 353 | 5.4 (4.3-6.9) | 5.5 (4.4-7.1) | 5.2 (4.1-6.6) | .14 |
| Creatinine, mg/dL | 593 | 0.60 (0.47-0.81) | 0.60 (0.46-0.81) | 0.61 (0.50-0.80) | .48 |
| Days on waitlist | 593 | 9 (5-21) | 9 (5-21) | 11 (5-22) | .22 |
| LAS at listing | 593 | 88 (85-90) | 88 (86-90) | 88 (84-90) | .053 |
| Center volume, annual | 593 | 54 (29-78) | 71 (54-95) | 23 (18-27) | <.001 |
| Waitlist outcome | 593 | < .001 | |||
| Died on waitlist | 148 (25) | 86 (21) | 62 (34) | ||
| Transplanted | 445 (75) | 326 (79) | 119 (66) |
a
Wilcoxon rank sum test; Pearson’s χ2 test; Fisher’s exact test. Values are presented as median (interquartile range) or n (%). LAS, lung allocation score.