Table 1.
Patient demographic and clinical characteristics, before and after matching-weights procedure
| Before matching-weights procedure | After matching-weights procedurea | |||||
|---|---|---|---|---|---|---|
| Variable | No RBC transfusion (0 unit) | Single-unit transfusion (1 unit) | ASMD | No RBC transfusion (0 unit) | Single-unit transfusion (1 unit) | ASMD |
| N | 4352 | 197 | 191.8 | 193.1 | ||
| Age | 68.0 (61.0–75.0) | 69.0 (61.0–76.0) | 0.168 | 70.0 (64.0–76.0) | 69.0 (63.0–76.0) | 0.010 |
| Male | 1862 (42.8) | 86 (43.7) | 0.018 | 83 (43.3) | 83 (42.9) | 0.008 |
| Pack-years | 32.0 (10.0–53.5) | 40.0 (20.0–61.2) | 0.260 | 40.8 (20.0–60.0) | 40.0 (20.0–62.1) | 0.023 |
| Smoking status | 0.203 | 0.023 | ||||
| Never | 714 (16.4) | 19 (9.6) | 17.8 (9.3) | 19.0 (9.8) | ||
| Former | 3039 (69.8) | 147 (74.6) | 144.7 (75.4) | 143.9 (74.5) | ||
| Current | 599 (13.8) | 31 (15.7) | 29.3 (15.3) | 30.3 (15.7) | ||
| Comorbidities | ||||||
| Pulmonary | 1277 (29.3) | 71 (36.0) | 0.143 | 68.1 (35.5) | 68.1 (35.2) | 0.006 |
| Cardiac | 2335 (53.7) | 125 (63.5) | 0.200 | 120.6 (62.9) | 121.9 (63.1) | 0.005 |
| Endocrine | 524 (12.0) | 33 (16.8) | 0.134 | 31.1 (16.2) | 32.0 (16.6) | 0.009 |
| Renal | 81 (1.9) | 10 (5.1) | 0.176 | 10.0 (5.2) | 9.0 (4.8) | 0.018 |
| Preop-Hemoglobin | 13.2 (12.1–14.1) | 11.3 (10.1–12.4) | 1.096 | 11.3 (10.5–12.5) | 11.3 (10.1–12.5) | 0.021 |
| SUV | 5.8 (2.7–10.7) | 10.8 (5.9–17.6) | 0.654 | 11.1 (6.2–16.0) | 10.4 (5.8–16.8) | 0.009 |
| FEV1 | 90.0 (77.0–103.0) | 84.0 (74.0–94.0) | 0.351 | 83.0 (70.0–96.0) | 84.0 (74.0–94.0) | 0.017 |
| DLCO | 80.0 (66.0–95.0) | 69.0 (59.0–80.0) | 0.565 | 68.0 (56.0–82.0) | 69.0 (59.0–88.0) | 0.011 |
| Neoadjuvant chemotherapy | 712 (16.4) | 93 (47.2) | 0.702 | 86.4 (45.1) | 89.4 (46.3) | 0.024 |
| Neoadjuvant radiation | 90 (2.1) | 17 (8.6) | 0.295 | 13.8 (7.2) | 15.6 (8.1) | 0.032 |
| ASA classification | 0.295 | 0.021 | ||||
| I | 12 (0.3) | 0 (0.0) | 0.0 (0.0) | 0.0 (0.0) | ||
| II | 1200 (27.7) | 32 (16.3) | 30.0 (15.6) | 31.7 (16.4) | ||
| III | 2986 (68.8) | 154 (78.6) | 152.0 (79.3) | 151.7 (78.5) | ||
| IV | 140 (3.2) | 10 (5.1) | 9.8 (5.1) | 9.8 (5.1) | ||
| Operation type | 0.400 | 0.023 | ||||
| Lobectomy | 3681 (84.6) | 153 (77.7) | 147.5 (76.9) | 150.0 (77.6) | ||
| Bilobectomy | 122 (2.8) | 10 (5.1) | 9.4 (4.9) | 9.6 (5.0) | ||
| Pneumonectomy | 152 (3.5) | 25 (12.7) | 25.2 (13.1) | 24.6 (12.7) | ||
| Segmentectomy | 397 (9.1) | 9 (4.6) | 9.7 (5.0) | 9.0 (4.7) | ||
| VATS | 1555 (35.7) | 19 (9.6) | 0.655 | 18.5 (9.6) | 19.0 (9.8) | 0.007 |
| Robot-assisted | 458 (10.5) | 11 (5.6) | 0.182 | 11.3 (5.9) | 11.0 (5.7) | 0.009 |
| Intrapericardial resection | 60 (1.4) | 10 (5.1) | 0.210 | 9.6 (5.0) | 9.7 (5.0) | 0.001 |
| Chest wall resection | 75 (1.7) | 21 (10.7) | 0.377 | 19.1 (9.9) | 19.0 (9.9) | 0.003 |
| Vascular resection | 24 (0.6) | 5 (2.5) | 0.162 | 4.2 (2.2) | 4.2 (2.2) | 0.001 |
| Pathologic stage | 0.540 | 0.017 | ||||
| IA | 1927 (44.3) | 48 (24.4) | 46.5 (24.2) | 47.2 (24.4) | ||
| IB | 871 (20.0) | 28 (14.2) | 27.3 (14.3) | 27.9 (14.4) | ||
| IIA | 565 (13.0) | 45 (22.8) | 43.8 (22.8) | 44.2 (22.9) | ||
| IIB | 288 (6.6) | 24 (12.2) | 24.3 (12.7) | 23.4 (12.1) | ||
| IIIA | 701 (16.1) | 52 (26.4) | 49.9 (26.0) | 50.5 (26.1) | ||
| Pathologic subtype | 0.403 | 0.044 | ||||
| Adenocarcinoma | 3272 (75.2) | 113 (57.4) | 107.2 (55.9) | 111.6 (57.4) | ||
| Adenosquamous | 66 (1.5) | 7 (3.6) | 7.0 (3.6) | 6.3 (3.3) | ||
| Invasive mucinous adenocarcinoma | 44 (1.0) | 1 (0.5) | 1.1 (0.6) | 1.0 (0.5) | ||
| Large cell carcinoma | 130 (3.0) | 11 (5.6) | 11.6 (6.1) | 10.9 (5.6) | ||
| Squamous cell carcinoma | 747 (17.2) | 59 (29.9) | 58.2 (30.4) | 57.4 (29.7) | ||
| Other NSCLC histologic subtype | 93 (2.1) | 6 (3.0) | 6.6 (3.5) | 6.0 (3.1) | ||
Data are no. (%) or median (interquartile range). ASA, American Society of Anesthesiologists physical status classification; ASMD, absolute standardized mean difference; DLCO, lung diffusion capacity of carbon monoxide; FEV1, forced expiratory volume in 1 second; NSCLC, non–small cell lung cancer; SUV, standardized uptake value; VATS, video-assisted thoracoscopic surgery.
a
The effective sample sizes may be nonintegers, as patients contribute a fraction of themselves to the analysis cohort on the basis of patient-level matching weights.