Table 1. Baseline patient characteristics.

Baseline characteristic	n [%]
Age (years), mean ± SD	73.8±8.2
Smoking status
Current smoker	7 [33]
Ex-smoker	14 [67]
Pack-years of smoking, mean ± SD	72.5±42.2
Body mass index (BMI), mean ± SD	25.7±6
Comorbidities
COPD	17 [81]
Obstructive sleep apnea	5 [21]
Coronary artery disease	6 [29]
Congestive heart failure	2 [10]
Stroke	4 [19]
Hypertension	16 [76]
Diabetes mellitus	10 [48]
End-stage renal disease	2 [10]
ASA score
I	–
II	1 [5]
III	17 [81]
IV	3 [14]
ECOG score
0	5 [24]
1	5 [24]
2	5 [24]
3	6 [28]
4	–

COPD, chronic obstructive pulmonary disease; ASA, American Society of Anesthesiologists; ECOG, Eastern Cooperative Oncology Group.