Patient characteristics at baseline
| UNOS listed | Unmatched Patients | NETT control | p-value¶ | Matched Patients | NETT control3 | p-value | |
| UNOS transplanted | UNOS transplanted | ||||||
| Subjects n | 5938 | 4521 | 604 | 401 | 262 | ||
| Demographics | |||||||
| Age years | 61 (56–64) | 61 (57–65) | 67 (64–71) | <0.0001 | 64 (61–67) | 65 (61–68) | 0.02 |
| ≥65 | 1445 (24) | 1287 (28) | 432 (72) | <0.0001 | 199 (50) | 152 (58) | 0.04 |
| Female sex | 3043 (51) | 2182 (48) | 219 (36) | <0.0001 | 177 (44) | 109 (42) | 0.52 |
| Race | 0.10 | 0.28 | |||||
| White | 5462 (92) | 4172 (92) | 569 (94) | 384 (96) | 246 (94) | ||
| Non-white | 476 (8) | 349 (8) | 35 (6) | 17 (4) | 16 (6) | ||
| BMI kg·m−2 | 24 (21–28)# | 24 (21–27)# | 25 (22–27)# | 0.12 | 25 (22–27) | 24 (21–28) | 0.76 |
| Disease severity | |||||||
| FVC % pred | 54 (43–65)# | 52 (41–64)# | 58 (48–68)# | <0.0001 | 55(47–65) | 55 (45–65) | 0.92 |
| FEV1 % pred | 20 (16–25)# | 20 (16–25)# | 24 (20–29)# | <0.0001 | 21 (18–25) | 22 (18–26) | 0.10 |
| 6 MWD ft | 760 (497–984)# | 770 (504–998)# | 1229 (990–1413)# | <0.0001 | 1000 (810–1191) | 1065 (860–1280) | 0.01 |
| 6 MWD m | 232 (151–300)# | 235 (154–304)# | 375 (302–431)# | 305 (247–363) | 325 (262–390) | ||
| 6 MWD <1000 ft (∼300 metre) or FEV1 <20% pred | 4035 (86)# | 4004 (89)# | 238 (39) | <0.0001 | 269 (67) | 151 (58) | 0.02 |
| O2 requirements at rest L | 3 (2–3)# | 3 (2–4)# | 1 (0–2) | <0.0001 | 2 (2–3) | 2 (2–2) | 0.04 |
| PCO2 mmHg | 47 (42–54)# | 49 (43–58)# | 43 (39–46) | <0.0001 | 45 (40–50) | 44 (40–49) | 0.49 |
| Mean PAP ≥35 mmHg | 555 (10)# | 455 (11)# | 0 (0)+ | 0 (0)+ | 0 (0)+ | ||
| Transplant characteristics | |||||||
| Type of lung transplant | |||||||
| Single | NA | 1756 (39)# | NA | 183 (46) | NA | ||
| Double | NA | 2764 (61)# | NA | 218 (54) | NA | ||
Data are presented as median (interquartile range) or n (%), unless otherwise stated. UNOS: United Network for Organ Sharing; NETT: National Emphysema Treatment Trial; BMI: body mass index; FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s; 6MWD: 6-min walk distance; PCO2: carbon dioxide tension; PAP: pulmonary arterial pressure. NA: not applicable. #: At least one patient was missing data on this variable, so statistics are based on patients with available data; ¶: p-value is for the comparison of the UNOS transplanted and NETT control groups; +: mean PAP≥35 was an exclusion criterion for NETT, so prior to matching, we excluded patients with PAP≥35.