Table 2.
Baseline demographic, clinical, laboratory, and tumor characteristics of the study cohort stratified by postoperative pneumonia status.
| Characteristic | Overall | (n = 467) | Postoperative pneumonia | p-value | |SMD| | |
|---|---|---|---|---|---|
| No | (n = 320) | Yes | (n = 147) | ||||
| Age (years) | 65.39 ± 6.63 | 65.41 ± 6.70 | 65.32 ± 6.51 | 0.890 | 0.014 |
| Sex | 0.210 | 0.125 | |||
| Female | 212 (45.4%) | 139 (43.4%) | 73 (49.7%) | ||
| Male | 255 (54.6%) | 181 (56.6%) | 74 (50.3%) | ||
| BMI (kg/m2) | 22.64 ± 2.35 | 22.65 ± 2.32 | 22.61 ± 2.43 | 0.866 | 0.017 |
| Smoking status | 0.298 | 0.104 | |||
| No | 308 (66.0%) | 216 (67.5%) | 92 (62.6%) | ||
| Yes | 159 (34.0%) | 104 (32.5%) | 55 (37.4%) | ||
| Alcohol consumption | 0.558 | 0.058 | |||
| No | 320 (68.5%) | 222 (69.4%) | 98 (66.7%) | ||
| Yes | 147 (31.5%) | 98 (30.6%) | 49 (33.3%) | ||
| Hypertension | 0.702 | 0.038 | |||
| No | 238 (51.0%) | 165 (51.6%) | 73 (49.7%) | ||
| Yes | 229 (49.0%) | 155 (48.4%) | 74 (50.3%) | ||
| Diabetes mellitus | 0.995 | 0.001 | |||
| No | 394 (84.4%) | 270 (84.4%) | 124 (84.4%) | ||
| Yes | 73 (15.6%) | 50 (15.6%) | 23 (15.6%) | ||
| Coronary heart disease | 0.481 | 0.072 | |||
| No | 303 (64.9%) | 211 (65.9%) | 92 (62.6%) | ||
| Yes | 164 (35.1%) | 109 (34.1%) | 55 (37.4%) | ||
| ASA physical status | 0.643 | 0.094 | |||
| I | 139 (29.8%) | 99 (30.9%) | 40 (27.2%) | ||
| II | 315 (67.5%) | 213 (66.6%) | 102 (69.4%) | ||
| III | 13 (2.8%) | 8 (2.5%) | 5 (3.4%) | ||
| FEV1/FVC (%) | 102.70 ± 12.02 | 102.12 ± 12.36 | 103.97 ± 11.19 | 0.111 | 0.156 |
| LVEF (%) | 65.95 ± 2.28 | 65.88 ± 2.35 | 66.11 ± 2.11 | 0.305 | 0.101 |
| Albumin (g/L) | 38.71 ± 4.15 | 39.91 ± 3.78 | 36.09 ± 3.72 | <0.001 | 1.018 |
| LDH (U/L) | 224.91 ± 45.29 | 214.43 ± 44.42 | 247.71 ± 38.36 | <0.001 | 0.802 |
| LAR | 5.90 ± 1.46 | 5.43 ± 1.30 | 6.93 ± 1.28 | <0.001 | 1.164 |
| Tumor location | 0.067 | 0.232 | |||
| Upper | 116 (24.8%) | 83 (25.9%) | 33 (22.4%) | ||
| Middle | 228 (48.8%) | 163 (50.9%) | 65 (44.2%) | ||
| Lower | 123 (26.3%) | 74 (23.1%) | 49 (33.3%) | ||
| Tumor length (cm) | 3.82 ± 0.69 | 3.84 ± 0.69 | 3.78 ± 0.69 | 0.388 | 0.086 |
| Tumor differentiation | 0.545 | 0.110 | |||
| Well | 27 (5.8%) | 18 (5.6%) | 9 (6.1%) | ||
| Moderate | 192 (41.1%) | 137 (42.8%) | 55 (37.4%) | ||
| Poor | 248 (53.1%) | 165 (51.6%) | 83 (56.5%) | ||
| pT category | 0.963 | 0.027 | |||
| T1 | 163 (34.9%) | 113 (35.3%) | 50 (34.0%) | ||
| T2 | 210 (45.0%) | 143 (44.7%) | 67 (45.6%) | ||
| T3 | 94 (20.1%) | 64 (20.0%) | 30 (20.4%) | ||
| pN category | 0.984 | 0.002 | |||
| N0 | 210 (45.0%) | 144 (45.0%) | 66 (44.9%) | ||
| N1 | 257 (55.0%) | 176 (55.0%) | 81 (55.1%) | ||
| pTNM stage | 0.881 | 0.051 | |||
| I | 160 (34.3%) | 112 (35.0%) | 48 (32.7%) | ||
| II | 213 (45.6%) | 144 (45.0%) | 69 (46.9%) | ||
| III | 94 (20.1%) | 64 (20.0%) | 30 (20.4%) | ||
Continuous variables are presented as mean ± standard deviation and compared using Welch’s t-test. Categorical variables are presented as n (%) and compared using the χ2 test or Fisher’s exact test, as appropriate. Absolute standardized mean differences (|SMD|) were calculated to quantify between-group imbalance. Tumor length was summarized among available cases (overall n = 466; no-pneumonia group n = 319; pneumonia group n = 147).