Table 1. Differences in clinical characteristics between the STAS-positive and STAS-negative groups.

Clinical characteristics	STAS-positive group (N=121)	STAS-negative group (N=121)	Stat†	P value
Gender			3.251	0.07
Male	64 (52.89)	50 (41.32)
Female	57 (47.11)	71 (58.68)
Age (years)	62.01±10.00	59.59±10.16	1.896	0.06
History of smoking			0.872	0.35
Yes	109 (90.08)	113 (93.39)
No	12 (9.92)	8 (6.61)

Data are presented as n (%) or mean ± standard deviation. ^†, In an independent samples t-test, the term “stat” refers to the t value. In a Mann-Whitney U test, “stat” refers to the Z value. For a chi-square test, “stat” refers to the Pearson value. STAS, spread through air spaces.