Table 3. Multivariate analysis of occult malignant pleural disease.

Variable	OR	95% CI	P value	coefficient
Age ≤50 years	1.781	0.988–3.211	0.055	0.577
Male	1.103	0.657–1.853	0.71	0.098
Non-smoking	0.786	0.521–2.365	0.786	0.105
CEA (ng/mL)	1.005	1.001–1.008	0.006	0.005
CA125 (U/mL)	1.001	0.999–1.003	0.324	0.001
N1 vs. N0	1.211	0.561–2.616	0.626	0.192
N2 vs. N0	2.266	1.286–3.990	0.005	0.818
Adenocarcinoma	7.232	2.227–23.486	0.001	1.979
Pleural invasion	1.709	1.022–2.858	0.041	0.536
Vascular thrombosis	1.581	0.843–2.965	0.154	0.458

CEA, carcinoembryonic antigen; CA125, carbohydrate antigen 125.