Table 1.
Propensity score calculation: Derived from 13 patient characteristics
| Confounding factors | Coeff | SE | P | Odds ratio (95% CI) |
|---|---|---|---|---|
| Age, y (continuous) | −0.04 | 0.009 | <0.001 | 0.96 (0.94‐0.98) |
| Male | −0.31 | 0.10 | 0.002 | 0.54 (0.36‐0.79) |
| BMI, n (%), kg/m2 | ||||
| ≥25 | 0.27 | 0.11 | 0.01 | 0.59 (0.38‐0.89) |
| 18.5‐25, reference | ‐ | ‐ | ‐ | ‐ |
| <18.5 | 0.17 | 0.12 | 0.21 | 0.71 (0.41‐1.22) |
| ASA≥3 | 0.60 | 0.22 | 0.007 | 0.30 (0.12‐0.69) |
| Comorbidity | 0.10 | 0.09 | 0.27 | 0.81 (0.57‐1.17) |
| Clinical T stage | ||||
| 3 | 0.05 | 0.22 | 0.81 | 0.90 (0.37‐2.11) |
| 4a, reference | ‐ | ‐ | ‐ | ‐ |
| 4b | 0.68 | 0.25 | 0.007 | 0.26 (0.09‐0.68) |
| Clinical N stage, positive | −0.05 | 0.10 | 0.61 | 0.91 (0.62‐1.33) |
| Clinical LLN involvement | 0.23 | 0.14 | 0.10 | 0.63 (0.37‐1.08) |
| Tumor distance from AV, cm (continuous) | 0.98 | 0.09 | <0.001 | 2.66 (2.23‐3.19) |
| Stenosis | 0.16 | 0.17 | 0.35 | 0.72 (0.37‐1.42) |
| Preoperative therapy | −0.24 | 0.10 | 0.02 | 1.60 (1.08‐2.39) |
| Laparoscopic approach | −0.16 | 0.10 | 0.10 | 1.38 (0.94‐2.03) |
| Hospital caseload ≥13/y | −0.29 | 0.09 | 0.001 | 1.78 (1.26‐2.53) |
ASA‐PS, American Society of Anesthesiologists Physical Status; AV, anal verge; BMI, body mass index; Coeff, regression coefficient; LLN, lateral pelvic lymph nodes; SE, standard error.