Table 4.

Correlation between independent variables and PPS

	Univariate Analysis			Multivariate Analysis
Independent variables	OR	95% CI	p-value	OR	95% CI	p-value
Gender (Male vs. Female)	1.868	1.074 – 3.250	0.027	1.076	0.535 – 2.166	0.837
Age	1.014	0.986 – 1.042	0.330	1.016	0.987 – 1.045	0.294
BMI	0.966	0.903 – 1.035	0.326	0.134	0.003 – 6.177	0.903
Smoking history (BI≥200 vs. BI<200)	2.529	1.332 – 4.804	0.005	2.023	0.920 – 4.451	0.080
Resected lobe (Others vs. Right upper lobectomy)	1.047	0.901 – 1.126	0.547	1.070	0.914 – 1.252	0.399
FEV1%	0.969	0.947 – 0.991	0.007	0.993	0.965 – 1.021	0.617
LAV%	1.055	1.024 – 1.088	<0.001	1.042	1.004 – 1.081	0.031

OR, odds ratio; CI, confidence interval; BMI, body mass index; BI, brinkman index; FEV₁, forced expiratory volume in 1 second; LAV, low-attenuation volume