Table 4.
Subgroup analysis using potential confounders as the stratification variables.
| Confounding factor category | N | AAPR group | P for trend | P for interaction | ||
|---|---|---|---|---|---|---|
| Low | Medium | High | ||||
| Age group, n (%) | 0.726 | |||||
| <67 | 124 (62.3) | 1 (reference) | 0.8 (0.31,2.08) | 0.4 (0.15,1.08) | 0.052 | |
| 67-73 | 51 (25.6) | 1 (reference) | 0.37 (0.13,1.05) | 0.17 (0.06,0.49) | 0.001* | |
| ≥74 | 24 (12.1) | 1 (reference) | 0.47 (0.12,1.81) | 0.13 (0.03,0.59) | 0.007* | |
| Sex, n (%) | 0.267 | |||||
| Female | 40 (20.1) | 1 (reference) | 1.04 (0.27,4.02) | 0.24 (0.05,1.2) | 0.04* | |
| Male | 159 (79.9) | 1 (reference) | 0.43 (0.22,0.87) | 0.25 (0.12,0.5) | < 0.001* | |
| BMI, n (%) | 0.504 | |||||
| <23.5 | 99 (49.7) | 1 (reference) | 0.33 (0.11,1.03) | 0.28 (0.12,0.65) | 0.004* | |
| ≥23.5 | 100 (50.3) | 1 (reference) | 0.39 (0.16,0.96) | 0.15 (0.05,0.41) | < 0.001* | |
| Smoking history, n (%) | 0.791 | |||||
| No | 111 (55.8) | 1 (reference) | 0.53 (0.18,1.52) | 0.31 (0.12,0.84) | 0.023* | |
| Yes | 88 (44.2) | 1 (reference) | 0.5 (0.23,1.08) | 0.19 (0.08,0.46) | < 0.001* | |
| ECOG-PS, n (%) | 0.738 | |||||
| 0 | 134 (67.3) | 1 (reference) | 0.56 (0.27,1.17) | 0.31 (0.15,0.65) | 0.002* | |
| 1 | 43 (21.6) | 1 (reference) | 0.47 (0.1,2.19) | 0.1 (0.02,0.55) | 0.006* | |
| 2 | 22 (11.1) | 1 (reference) | 0.55 (0.1,3.14) | 0.26 (0.04,1.88) | 0.175 | |
| Diabetes, n (%) | 0.367 | |||||
| No | 164 (82.4) | 1 (reference) | 0.47 (0.24,0.92) | 0.23 (0.12,0.45) | < 0.001* | |
| Yes | 35 (17.6) | 1 (reference) | 1.04 (0.21,5.23) | 0.17 (0.01,1.85) | 0.097 | |
| Hypertension, n (%) | 0.912 | |||||
| No | 165 (82.9) | 1 (reference) | 0.55 (0.28,1.06) | 0.24 (0.12,0.48) | < 0.001* | |
| Yes | 34 (17.1) | 1 (reference) | 0.35 (0.06,1.93) | 0.19 (0.04,0.87) | 0.034* | |
| Chemotherapy, n (%) | 0.234 | |||||
| No | 164 (82.4) | 1 (reference) | 0.5 (0.26,0.96) | 0.28 (0.14,0.54) | < 0.001* | |
| Yes | 35 (17.6) | 1 (reference) | 1.07 (0.12,9.91) | 0.11 (0.01,1.9) | 0.034* | |
| ASA classification, n (%) | 0.613 | |||||
| 1 | 40 (20.1) | 1 (reference) | 0.23 (0.05,0.99) | 0.15 (0.04,0.67) | 0.016* | |
| 2 | 130 (65.3) | 1 (reference) | 0.71 (0.32,1.55) | 0.26 (0.11,0.57) | < 0.001* | |
| 3 | 29 (14.6) | 1 (reference) | 0.72 (0.16,3.24) | 0.38 (0.08,1.9) | 0.227 | |
| T-stage, n (%) | 0.758 | |||||
| T1-T2 | 166 (83.4) | 1 (reference) | 0.53 (0.26,1.07) | 0.22 (0.1,0.46) | < 0.001* | |
| T3-T4 | 33 (16.6) | 1 (reference) | 0.6 (0.17,2.12) | 0.29 (0.08,1.08) | 0.058 | |
| Lymph node status, n (%) | 0.536 | |||||
| Negative | 160 (80.4) | 1 (reference) | 0.51 (0.25,1.07) | 0.2 (0.09,0.44) | < 0.001* | |
| Positive | 39 (19.6) | 1 (reference) | 0.71 (0.22,2.23) | 0.46 (0.15,1.4) | 0.171 | |
| Tumor grade, n (%) | 0.393 | |||||
| Low | 117 (58.8) | 1 (reference) | 0.49 (0.19,1.23) | 0.18 (0.07,0.48) | < 0.001* | |
| High | 82 (41.2) | 1 (reference) | 0.76 (0.32,1.79) | 0.41 (0.18,0.98) | 0.033* | |
| HGB, n (%) | 0.042* | |||||
| <130 | 102(51.3) | 1 (reference) | 0.57 (0.27,1.24) | 0.11 (0.04,0.31) | < 0.001* | |
| ≥130 | 97(48.7) | 1 (reference) | 0.53 (0.19,1.48) | 0.47 (0.18,1.24) | 0.183 | |
*P < 0.05. AAPR, albumin-to-alkaline phosphatase ratio; ECOG-PS, Performance Status of East Cooperative Oncology Group; ASA, American Society of Anesthesiologists; HGB, Hemoglobin.