Table 2. Univariate and multivariable logistic regression analyses of variables for PPCs after thoracoscopic surgery in the training cohort.

Project		Univariate analysis		Multivariate analysis
		OR (95% CI)	p -value	OR (95% CI)	p -value
Age (years)	≤45	Ref
	46–55	2.515 (1.066–6.622)	0.045
	56–65	5.250 (2.416–13.155)	<0.001
	66–75	10.428 (4.930–25.704)	<0.001
	>75	17.309 (7.097–47.375)	<0.001
Sex	female	Ref
	male	1.782 (1.215–2.653)	0.004
ASA	I/II	Ref		Ref
	III/IV	14.776 (9.485–23.437)	<0.001	10.171 (5.598–18.926)	<0.001
MAP (mmHg)	70–105	Ref
	<70	0.404 (0.022–2.190)	0.392
	>105	1.216 (0.857–1.724)	0.273
Duration of operation (min)	<180	Ref		Ref
	180–300	3.229 (2.073–5.037)	<0.001	2.480 (1.363–4.563)	0.003
	>300	8.524 (5.414–13.563)	<0.001	12.516 (5.232–17.766)	<0.001
Airway management	Bronchial occluder	Ref
	double-lumen	1.335 (0.438–5.800)	0.650
	LMA	2.774 (0.909–12.067)	0.109
	single-lumen	0.000 (0.000–0.000)	0.979
Duration of one-lung ventilation (min)	≤60	Ref		Ref
	>60	1.000 (1.000–1.000)	<0.001	2.947 (1.257–7.648)	0.018
BMI (kg/m 2 )	<18.5	Ref
	18.5–24	0.625 (0.344–1.080)	0.105
	24–28	0.942 (0.619–1.417)	0.777
	≥28	1.516 (0.277–1.395)	0.306
History of hypertension	No	Ref
	Yes	1.481 (0.999–2.177)	0.048
History of diabetes mellitus	No	Ref
	Yes	1.812 (0.880–3.567)	0.093
History of stroke	No	Ref		Ref
	Yes	5.022 (2.472–10.442)	<0.001	4.209 (1.518–11.683)	0.006
History of heart disease	No	Ref		Ref
	Yes	7.233 (4.171–12.832)	<0.001	2.001 (0.901–4.479)	0.089
History of COPD	No	Ref		Ref
	Yes	7.345 (3.871–14.467)	<0.001	2.888 (1.230–6.980)	0.016
History of smoking	No	Ref		Ref
	Yes	5.962 (4.083–8.753)	<0.001	4.101 (2.544–6.654)	<0.001
History of alcohol use	No	Ref
	Yes	1.594 (0.760–3.168)	0.196
Leukocyte counts (×10 9 /L)	4–10	Ref
	<4	1.325 (0.760–2.234)	0.304
	>10	1.570 (0.633–3.577)	0.301
Red blood cell counts (×10 12 /L)	Normal	Ref
	Low	1.828 (1.157–2.850)	0.009
	Hight	0.927 (0.262–2.580)	0.894
Platelet counts (×10 9 /L)	100–300	Ref
	<100	1.227 (0.472–2.852)	0.650
	>300	0.740 (0.314–1.548)	0.454
Aspartate aminotransferase (U/L)	<40	Ref
	≥40	0.971 (0.463–1.883)	0.934
Alanine aminotransferase (U/L)	<50	Ref
	≥50	1.413 (0.444–3.871)	0.522
Blood glucose (mmol/L)	Normal	Ref
	Abnormal	0.882 (0.509–1.468)	0.641
Blood creatinine (µmol/L)	<111	Ref
	≥111	2.135 (0.638–6.489)	0.189
Blood urea nitrogen (mmol/L)	<9.5	Ref
	≥9.5	1.572 (0.545–4.047)	0.367
Serum sodium (mmol/L)	137–147	Ref
	<137	1.143 (0.367–3.003)	0.799
	>147	2.143 (0.640–6.518)	0.187
Serum potassium (mmol/L)	Normal	Ref
	Abnormal	1.566 (0.790–2.964)	0.181
Serum albumin (g/L)	Normal	Ref
	Low	1.611 (1.134–2.300)	0.008
Types of operation	Wege resection	Ref
	Trans-thoracic vagotomy	0.000 (0.000–0.000)	0.983
	Segmental resection	1.180 (0.533–2.717)	0.687
	Lobectomy	1.687 (0.859–3.578)	0.147
	Total pneumonectomy	0.000 (0.000,inf)	0.989
	Partial bilateral pneumonectomy	2.005 (0.571–6.333)	0.248
	Mediastinal surgery	0.290 (0.044–1.142)	0.118
	Esophageal surgery	6.069 (3.122–12.808)	<0.001
	Others	0.524 (0.028–3.062)	0.553

Notes.

Blood laboratory data were routine examination results before the operation.

OR

odds ratio

CI

confidence interval

ASA

American Society of Anesthesiologists

MAP

mean arterial pressure

LMA

laryngeal mask airway

COPD

chronic obstructive pulmonary disease