表 5.

不同镇痛时间组的RR

Relative risks in groups with different ELA durations

ELA duration	n	Group ESA (n=615)	Group SA (n=186)	RR	95% CI	P
ESA: Epidural surgery anesthesia; SA: Spinal anesthesia; ELA: Epidural labor analgesia.
> 9.5 h	301	205(68.1%)	96(31.9%)	1.204	1.103~2.341	< 0.001
< 9.5 h	500	410(82.0%)	90(18.0%)	0.564	0.440~0.724	< 0.001