Table 1.

Comparison of general data between the two groups

	WAA group (n = 91)	CON group (n = 90)	t value/χ2 value	P value
Sex (male/female)	40/51	46/44	0.93	0.33
Age (years-old)	49.34 ± 1.11	49.73 ± 1.12	0.25	0.80
Body mass index (kg)	67.75 ± 13.58	65.54 ± 11.50	1.18	0.24
Operation time of examination (min)	15.98 ± 0.66	16.08 ± 0.63	0.11	0.91