Table 4:

Multivariable Cox proportional hazards model

Characteristic	Hazard ratio	95% CI	P-value
Approach	0.56	0.32–1.01	0.053
Age	1.01	0.99–1.03	0.17
Sex	0.90	0.61–1.33	0.61
FEV1	1.00	0.99–1.02	0.56
DLCO	0.99	0.98–1.00	0.11
Cerebrovascular disease	0.96	0.35–2.66	0.94
Diabetes	1.09	0.65–1.83	0.73
Zubrod score
0	Ref	Ref	Ref
1	0.68	0.46–1.01	0.055
2 and 3a	2.49	0.73–8.52	0.15
Renal insufficiency	1.08	0.25–4.72	0.92
Congestive heart failure	1.45	0.49–4.27	0.50
Coronary artery disease	0.95	0.54–1.68	0.86
Prior thoracic surgery	1.49	0.96–2.30	0.077
Radiation	1.22	0.78–1.19	0.39
COPD	1.62	1.01–2.62	0.047
Pretreatment histology
Adenocarcinoma	Ref	Ref	Ref
Adenosquamous	0.99	0.13–7.45	0.99
Squamous	1.01	0.66–1.53	0.98
Large cell	0.89	0.41–1.92	0.76
Non-small cell, not otherwise specified	0.57	0.34–0.96	0.033
Clinical stage prior to induction therapy	1.00	0.99–1.01	0.68
History of smoking	2.09	0.62–7.03	0.23
Operative year	1.02	0.96–1.08	0.45

VATS: video-assisted thoracoscopic surgery; COPD: chronic obstructive pulmonary disease; SD: standard deviation; FEV1: forced expiratory volume in 1 s; DLCO: diffusing capacity of the lung for carbon monoxide.

^aZubrod scores 2 and 3 were combined into one category to simplify the output because there was only 1 patient in the entire cohort with a Zubrod score of 3.