Table 3. Univariable analysis of gender-specific risk factors for PAL.
| Characteristics | Male | Female | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Total (N=616) | With PAL (N=117) | Without PAL (N=499) | P value | Total (N=475) | With PAL (N=42) | Without PAL (N=433) | P value | ||
| Basic information | |||||||||
| Age (years) | |||||||||
| Mean ± SD | 61.4±8.7 | 63.1±8.1 | 61.0±8.8 | 0.037 | 61.4±8.8 | 62.8±8.0 | 61.3±8.9 | 0.24 | |
| Median (IQR) | 62 (55–68) | 63 (58–69) | 62 (54–67) | 62 (56–67) | 63 (58–67) | 62 (56–67) | |||
| Body mass index (kg/m2) | |||||||||
| Mean ± SD | 23.6±3.0 | 22.9±3.2 | 23.7±3.0 | 0.004 | 23.0±3.0 | 21.9±2.9 | 23.2±3.0 | 0.003 | |
| Median (IQR) | 23.5 (21.3–25.6) | 22.5 (20.7–25.0) | 23.7 (21.6–25.8) | 22.9 (20.8–24.8) | 21.8 (19.8–23.5) | 23.1 (21.0–24.9) | |||
| Fat–free mass index (kg/m2) | |||||||||
| Mean ± SD | 17.3±1.5 | 16.9±1.5 | 17.4±1.5 | 0.002 | 14.5±1.1 | 14.0±0.9 | 14.6±1.1 | <0.001 | |
| Median (IQR) | 17.3 (16.3–18.4) | 16.9 (15.8–18.2) | 17.5 (16.3–18.4) | 14.6 (13.8–15.3) | 14.0 (13.4–14.8) | 14.7 (13.9–15.3) | |||
| Body fat percentage (%) | |||||||||
| Mean ± SD | 26.2±4.0 | 25.8±4.1 | 26.3±4.0 | 0.10 | 36.4±4.5 | 35.3±4.7 | 36.5±4.5 | 0.078 | |
| Median (IQR) | 26.1 (23.6–28.9) | 25.3 (23.2–28.0) | 26.2 (23.7–29.2) | 36.2 (33.4–39.1) | 35.3 (32.6–38.6) | 36.4 (33.5–39.2) | |||
| FEV1% | |||||||||
| Mean ± SD | 77.5±15.0 | 73.1±16.5 | 78.5±14.4 | <0.001 | 88.3±16.0 | 86.1±18.0 | 88.5±15.8 | 0.39 | |
| Median (IQR) | 81.5 (68.8–86.5) | 78.1 (59.8–84.2) | 82.3 (71.5–86.5) | 87.1 (78.5–98.0) | 85.5 (76.9–98.5) | 87.1 (78.5–98.0) | |||
| FEV1/FVC (%) | |||||||||
| Mean ± SD | 74.9±10.1 | 73.5±11.2 | 75.3±9.8 | 0.040 | 78.5±7.8 | 77.6±9.5 | 78.5±7.6 | 0.39 | |
| Median (IQR) | 77.0 (72.0–80.9) | 75.2 (69.0–80.7) | 77.1 (72.5–81.0) | 78.9 (73.9–84.0) | 75.4 (73.1–83.9) | 78.9 (74.0–84.0) | |||
| Smoking history | 472 (76.6%) | 96 (82.1%) | 376 (75.4%) | 0.12 | 15 (3.2%) | 0 (0.0%) | 15 (3.5%) | 0.45 | |
| Respiratory comorbidity | 313 (50.8%) | 80 (68.4%) | 233 (46.7%) | <0.001 | 144 (30.3%) | 20 (47.6%) | 124 (28.6%) | 0.011 | |
| Cardio-cerebrovascular comorbidity | 250 (40.6%) | 58 (49.6%) | 192 (38.5%) | 0.028 | 172 (36.2%) | 20 (47.6%) | 152 (35.1%) | 0.11 | |
| Diabetes mellitus | 88 (14.3%) | 13 (11.1%) | 75 (15.0%) | 0.28 | 43 (9.1%) | 6 (14.3%) | 37 (8.5%) | 0.34 | |
| Renal insufficiency | 53 (8.6%) | 13 (11.1%) | 40 (8.0%) | 0.28 | 39 (8.2%) | 5 (11.9%) | 34 (7.9%) | 0.54 | |
| Previous malignancy | 56 (9.1%) | 15 (12.8%) | 41 (8.2%) | 0.12 | 50 (10.5%) | 6 (14.3%) | 44 (10.2%) | 0.57 | |
| Steroid use | 26 (4.2%) | 4 (3.4%) | 22 (4.4%) | 0.82 | 10 (2.1%) | 2 (4.8%) | 8 (1.8%) | 0.49 | |
| Adjuvant chemotherapy | 185 (30.0%) | 41 (35.0%) | 144 (28.9%) | 0.19 | 57 (12.0%) | 2 (4.8%) | 55 (12.7%) | 0.13 | |
| Intraoperative parameters | |||||||||
| Tumor location | |||||||||
| Right upper lobe | 186 (30.2%) | 27 (23.1%) | 159 (31.9%) | 0.24 | 153 (32.2%) | 16 (38.1%) | 137 (31.6%) | 0.10 | |
| Left upper lobe | 144 (23.4%) | 28 (23.9%) | 116 (23.2%) | 119 (25.1%) | 14 (33.3%) | 105 (24.2%) | |||
| Right lower lobe | 121 (19.6%) | 28 (23.9%) | 93 (18.6%) | 88 (18.5%) | 9 (21.4%) | 79 (18.2%) | |||
| Left lower lobe | 92 (14.9%) | 16 (13.7%) | 76 (15.2%) | 66 (13.9%) | 1 (2.4%) | 65 (15.0%) | |||
| Right middle lobe | 73 (11.9%) | 18 (15.4%) | 55 (11.0%) | 49 (10.3%) | 2 (4.8%) | 47 (10.9%) | |||
| Dense pleural adhesion | |||||||||
| Absent | 549 (89.1%) | 97 (82.9%) | 452 (90.6%) | 0.016 | 433 (91.2%) | 34 (81.0%) | 399 (92.1%) | 0.031 | |
| Present | 67 (10.9%) | 20 (17.1%) | 47 (9.4%) | 42 (8.8%) | 8 (19.0%) | 34 (7.9%) | |||
| Pulmonary fissure completeness | |||||||||
| Complete | 354 (57.5%) | 40 (34.2%) | 314 (62.9%) | <0.001 | 308 (64.8%) | 20 (47.6%) | 288 (66.5%) | 0.014 | |
| Incomplete | 262 (42.5%) | 77 (65.8%) | 185 (37.1%) | 167 (35.2%) | 22 (52.4%) | 145 (33.5%) | |||
| Estimated intraoperative blood loss (mL) | |||||||||
| Mean ± SD | 91.1±117.9 | 148.1±202.7 | 77.7±81.8 | <0.001 | 55.1±60.0 | 67.6±81.1 | 53.9±57.5 | 0.13 | |
| Median (IQR) | 50 (30–100) | 90 (43–200) | 50 (30–100) | 50 (20–50) | 50 (30–65) | 50 (20–50) | |||
| Operation time (min) | |||||||||
| Mean ± SD | 119.0±43.3 | 140.9±52.4 | 113.8±39.2 | <0.001 | 106.7±34.8 | 132.6±43.4 | 104.2±32.9 | <0.001 | |
| Median (IQR) | 110 (90–135) | 125 (110–160) | 105 (90–130) | 100 (80–120) | 120 (100–153) | 100 (80–120) | |||
| Pathological parameters | |||||||||
| Histology | |||||||||
| Adenocarcinoma | 418 (67.9%) | 73 (62.4%) | 345 (69.1%) | 0.13 | 413 (86.9%) | 39 (92.9%) | 374 (86.4%) | 0.44 | |
| Squamous cell carcinoma | 146 (23.7%) | 36 (30.8%) | 110 (22.0%) | 19 (4.0%) | 1 (2.4%) | 18 (4.2%) | |||
| Other subtypes of NSCLC | 52 (8.4%) | 8 (6.8%) | 44 (8.8%) | 43 (9.1%) | 2 (4.8%) | 41 (9.5%) | |||
| Tumor invasion (T-stage) | |||||||||
| T1 | 255 (41.4%) | 38 (32.5%) | 217 (43.5%) | 0.030 | 292 (61.5%) | 28 (66.7%) | 264 (61.0%) | 0.47 | |
| T2–3 | 361 (58.6%) | 79 (67.5%) | 282 (56.5%) | 183 (38.5%) | 14 (33.3%) | 169 (39.0%) | |||
| Lymph node metastasis (N-stage) | |||||||||
| N0 | 471 (76.5%) | 78 (66.7%) | 393 (78.8%) | 0.006 | 432 (90.9%) | 39 (92.9%) | 393 (90.8%) | 0.87 | |
| N1–2 | 145 (23.5%) | 39 (33.3%) | 106 (21.2%) | 43 (9.1%) | 3 (7.1%) | 40 (9.2%) | |||
| TNM-stage | |||||||||
| I | 407 (66.1%) | 66 (56.4%) | 341 (68.3%) | 0.014 | 405 (85.3%) | 36 (85.7%) | 369 (85.2%) | 0.93 | |
| II–IIIa | 209 (33.9%) | 51 (43.6%) | 158 (31.7%) | 70 (14.7%) | 6 (14.3%) | 64 (14.8%) | |||
FEV1, forced expiratory volume in one second; FEV1/FVC, forced expiratory volume in one second to forced volume capacity ratio; IQR, interquartile range; PAL, prolonged air leak; SD, standard deviation.