Table 4.

Clinical outcomes between the two groups

	Early group (n = 20)	Late group (n = 62)	OR or difference	95% CI	P value
VAS for low back pain
Preoperative	5.60 ± 1.82	5.29 ± 1.68	0.31 ± 0.546	− 0.791–1.422	0.568†
1 week	3.45 ± 1.79	3.00 ± 1.00	0.45 ± 0.45	− 0.462–1.366	0.324†
1 month	2.71 ± 1.40	2.47 ± 1.74	0.24 ± 0.54	− 0.878–1.342	0.667†
6 months	2.89 ± 1.69	2.80 ± 1.32	0.09 ± 0.62	− 1.194–1.371	0.887†
VAS for leg pain
Preoperative	6.15 ± 1.63	6.05 ± 1.75	0.10 ± 0.53	− 0.977–1.174	0.847†
1 week	4.00 ± 1.56	3.81 ± 2.09	0.019 ± 0.58	− 0.983–1.367	0.743†
1 month	3.53 ± 2.15	3.18 ± 2.60	0.35 ± 0.82	− 1.320–2.022	0.670†
6 months	3.56 ± 1.67	3.60 ± 2.35	0.04 ± 0.90	− 1.917–1.821	0.961†
Odom’s criteria
1 week, Excellent/good/fair/poor	2/11/6/1	8/29/24/1			0.577‡
1 month, Excellent/good/fair/poor	3/8/9/0	17/20/25/0			0.383‡
6 months, Excellent/good/fair/poor	2/9/7/2	14/23/23/2			0.231‡

CI confidence interval, OR odds ratio, VAS visual analog scale

^†Independent t-test, ‡Pearson’s Chi square test