Table 2.

Preoperative predictive factors

(a) Cox proportional hazards univariate analysis
Predictive factor	Odds ratio	95% Confidence interval	p-value
Preoperative comorbidity
Cardiac	0.805	0.144–4.501	0.8046
Lung	0.244	0.029–2.042	0.1930
Kidney	0.756	0.149–3.837	0.7353
Diabetes mellitus	0.504	0.097–2.624	0.4159
Hypertension	4.932	0.987–24.637	0.0518
Smoking status
Brinkman index	1.001	1–1.001	0.0318*
Smoking cessation period	1.012	0.947–1.081	0.7239
Preoperative CT image
Tumor size	0.477	0.887–2.926	0.1171
PA:A ratio	4.35E-05	1.043E-8–0.181	0.0182*
Preoperative condition
BMI	1.078	0.850–1.367	0.5368
eGFR	1.021	0.982–1.061	0.3016
Preoperative pulmonary function test
%VC	0.948	0.896–1.004	0.0668
%FEV1.0	0.976	0.933–1.021	0.2853
%DLCO	0.984	0.937–1.033	0.5136
%TLC	1.004	0.917–1.100	0.9262
Lung age	1.004	0.976–1.034	0.7680
A–aDO2	1.118	1.011–1.236	0.0300*
Operative procedure
Partial resection	7.055	0.8654–57.51	0.0680

^*statistically significant; CT: computed tomography; PA:A: the pulmonary artery diameter to the ascending aorta diameter; BMI: body mass index; eGFR: estimated glomerular filtration rate; VC: vital capacity; FEV_1.0: forced expiratory volume in 1 s; DLCO: diffusing capacity for carbon monoxide; TLC: total lung capacity; A–aDO₂: alveolar– arterial oxygen gradient