表 3. Comparison of complication incidence between the two groups before and after PSM.

匹配前、后两组的并发症发生率

Matching	Complications	Observation group/times (%)	Control group/times (%)	χ 2	P
Before	Yes	6 (8.3)	65 (30.2)	13.893	<0.01
	No	66 (91.7)	150 (69.8)
	Total	72 (100)	215 (100)	35.200	<0.01
After	Yes	6 (8.3)	39 (54.2)
	No	66 (91.7)	33 (45.8)
	Total	72 (100)	72 (100)