Table 4

Postoperative improvement of outcomes between groups.

Patient-Reported Outcome Measures	Non-WC, Mean ± SD (n)	P Value^a	WC, Mean ± SD (n)	P Value^a	P Value^b
VAS back
Preoperative	6.0 ± 2.6 (92)	–	6.7 ± 2.2 (29)	–	0.297
6 wk	3.3 ± 2.6 (83)	<0.001	5.1 ± 2.0 (25)	0.001	0.001
12 wk	2.6 ± 2.2 (76)	<0.001	5.3 ± 2.5 (24)	0.004	<0.001
6 mo	2.5 ± 2.4 (75)	<0.001	5.3 ± 2.5 (25)	0.007	<0.001
1 y	2.2 ± 2.4 (48)	<0.001	4.7 ± 2.7 (13)	0.147	0.004
VAS leg
Preoperative	5.3 ± 3.0 (92)	–	5.0 ± 3.0 (29)	–	0.475
6 wk	2.5 ± 2.5 (83)	<0.001	4.1 ± 2.7 (25)	0.188	0.012
12 wk	1.9 ± 2.4 (77)	<0.001	3.6 ± 2.7 (24)	0.032	0.004
6 mo	1.6 ± 2.5 (75)	<0.001	3.4±2.5 (25)	0.044	<0.001
1 y	1.9 ± 2.9 (48)	<0.001	4.1 ± 2.7 (13)	0.223	0.002
ODI
Preoperative	35.8 ± 13.9 (92)	–	45.1 ± 15.6 (29)	–	0.003
6 wk	28.5 ± 18.1 (84)	<0.001	46.6 ± 17.3 (25)	0.696	<0.001
12 wk	22.4 ± 15.8 (78)	<0.001	43.5 ± 14.3 (24)	0.439	<0.001
6 mo	15.7 ± 13.6 (76)	<0.001	39.1 ± 18.9 (25)	0.088	<0.001
1 y	15.7 ± 18.7 (48)	<0.001	30.3 ± 21.3 (13)	0.071	0.009
SF-12 PCSy
Preoperative	32.4 ± 8.0 (88)	–	27.4 ± 6.6 (27)	–	0.001
6 wk	34.0 ± 9.2 (77)	0.138	26.3 ± 6.0 (22)	0.319	0.001
12 wk	38.1 ± 10.6 (68)	0.001	27.5 ± 5.7 (23)	0.775	<0.001
6 mo	42.9 ± 11.0 (62)	<0.001	28.3 ± 7.0 (18)	0.581	<0.001
1 y	43.1 ± 10.8 (54)	<0.001	30.8 ± 10.1 (15)	0.401	<0.001
PROMIS-PF
Preoperative	36.4 ± 4.9 (92)	–	32.6 ± 5.3 (29)	–	0.001
6 wk	38.2 ± 6.9 (77)	0.017	33.7 ± 5.5 (21)	0.444	0.004
12 wk	42.2 ± 6.4 (62)	<0.001	37.2 ± 6.3 (18)	0.043	0.005
6 mo	45.3 ± 6.7 (63)	<0.001	39.2 ± 7.3 (16)	<0.001	0.003
1 y	47.2 ± 8.2 (57)	<0.001	39.0 ± 8.5 (12)	0.022	0.004

Boldface indicates statistical significance.
aP value was calculated using paired t test.
bP values calculated using Mann-Whitney U test.
ODI, Oswestry Disability Index; PROMIS-PF, Patient-Reported Outcome Measurement Information System physical function; SF-12, 12-Item Short Form Physical Component Summary; VAS, visual analog scale; WC, workers’ compensation.