Table 4.

Patient-Reported Outcomes Measures of Included Studies.

	Direct			Indirect
Measurement	Mean	SD	# of studies	Mean	SD	# of studies	P-value
ODI
Pre-Op ODI	36.5	12.8	3	44.4	8.8	12	.17
Post-Op ODI	19.4	10.3	3	23.1	8.3	12	.30
ODI difference	−17.1	3.5	3	−21.3	7.2	12	.05 ^
VAS back pain
Pre-Op VAS back pain	7.0	1.8	3	7.1	0.8	13	.40
Post-Op VAS back pain	2.7	0.6	3	2.9	1.0	13	.34
VAS back pain difference	−4.3	1.5	3	−4.2	0.9	13	.46
VAS leg pain
Pre-Op VAS leg pain	4.9	2.9	2	6.8	1.6	8	.37
Post-Op VAS leg pain	2.3	0.8	2	2.2	0.5	8	.34
VAS leg pain difference	−2.7	2.0	2	−4.6	1.6	8	.27

Abbreviations: ODI, Oswestry disability index; VAS, visual analog scale.

^ Insignificant Difference.