Table 1.

Baseline characteristics.

	All subjects	AE-ILD ( +)	AE-ILD (-)	P-value*
Subjects, n (%)	152	17 (11.2)	135 (88.8)
Age, years	72.9 ± 7.5	71.7 ± 7.5	73.1 ± 7.5	0.487
Sex, male/female	126/26	17/0	109/26	0.045
Smoking history, pack-years	50.0 (30.0–67.5)	60.0 (39.0–95.0)	47.5 (30.0–65.6)	0.211
VC, % predicted	90.8 ± 16.2	81.9 ± 17.1	91.9 ± 15.8	0.016
FVC, % predicted	87.9 ± 15.2	81.8 ± 16.8	88.7 ± 14.8	0.076
FEV1, % predicted	87.9 ± 17.8	79.8 ± 18.2	88.9 ± 17.6	0.046
FEV1/FVC, %	75.7 ± 10.4	79.0 ± 8.1	75.3 ± 10.6	0.164
DLco, % predicted	56.5 ± 17.4	51.2 ± 21.1	57.2 ± 16.8	0.237
ILD pattern				0.445
UIP	48	8	40
Probable UIP	17	2	15
Indeterminate UIP	48	3	45
Alternative diagnosis	39	4	35
Preoperative steroid use, + /−	15/137	2/15	13/122	0.676
Preoperative pirfenidone use, + /−	6/146	1/16	5/130	0.664
Histology				0.689
Adenocarcinoma	68	6	62
Squamous cell carcinoma	56	7	49
Small cell carcinoma	11	2	9
Others	17	2	15
pStage, I/II/IIIA/IIIB	119/17/13/3	13/2/1/1	106/15/12/2	0.746
Primary tumor size, mm	24 (17–34)	33 (21–37)	22 (16–33)	0.057
Surgical intervention				0.474
Sublobar resection**	75	7	68
Lobectomy	77	10	67
Operative time, min	149 (108–196)	200 (138–252)	146 (106–181)	0.022
Bleeding volume, mL	66 (23–110)	155 (73–301)	60 (22–100)	0.003

Data are presented as mean ± standard deviation or median (interquartile range) according to their distribution.

AE-ILD acute exacerbation of interstitial lung disease; DLco diffusing capacity for carbon monoxide; FEV1 forced expiratory volume in one second; FVC forced vital capacity; ILD interstitial lung disease; UIP usual interstitial pneumonia; VC vital capacity.

*All P-values were evaluated by comparing patients with and without postoperative AE-ILD using the t-test and Mann–Whitney U tests for normally and non-normally distributed variables, respectively, and using Pearson’s chi-squared test.

**Sublobar resection group included 41 patients treated with wedge resection and 34 patients treated with segmentectomy.