Table 9.

 Secondary outcomes in patients with low back pain and degenerative disc randomised to disc prosthesis surgery or rehabilitation. Mean (SD) outcome values on EQ-5D, HSCL-25, FABQ, and self efficacy at follow-up and treatment effect (difference (95% confidence interval))

Variable*	Surgery	Rehabilitation	Treatment effect†
EQ-5D‡
Baseline	0.30 (0.30)	0.27 (0.31)	—
6 weeks	0.59 (0.30)	0.55 (0.29)	0.04 (−0.06 to 0.15)
3 months	0.70 (0.23)	0.48 (0.31)	0.22 (0.12 to 0.33)
6 months	0.68 (0.28)	0.51 (0.33)	0.17 (0.06 to 0.27)
1 year	0.67 (0.35)	0.54 (0.32)	0.13 (0.02 to 0.23)
2 years	0.68 (0.34)	0.60 (0.30)	0.08 (−0.03 to 0.18)
HSCL-25§
Baseline	1.81 (0.50)	1.88 (0.51)	—
3 months	1.38 (0.34)	1.66 (0.51)	−0.27 (−0.44 to −0.11)
6 months	1.44 (0.45)	1.66 (0.49)	−0.22 (−0.38 to −0.05)
1 year	1.45 (0.50)	1.59 (0.49)	−0.14 (−0.30 to 0.03)
2 years	1.47 (0.49)	1.55 (0.50)	−0.09 (−0.25 to 0.08)
FABQ work§
Baseline	25.8 (11.2)	27.4 (9.9)	—
3 months	20.0 (12.9)	24.3 (11.9)	−4.3 (−8.6 to 0.1)
6 months	18.7 (12.9)	23.0 (12.7)	−4.3 (−8.7 to 0.1)
1 year	18.2 (13.9)	21.3 (13.2)	−3.1 (−7.4 to 1.2)
2 years	16.7 (13.5)	18.5 (12.5)	−1.8 (−6.1 to 2.5)
FABQ physical§
Baseline	14.0 (5.8)	12.5 (5.6)	—
3 months	8.8 (5.3)	9.1 (6.3)	−0.3 (−2.4 to 1.7)
6 months	8.6 (6.3)	9.3 (6.7)	−0.7 (−2.8 to 1.3)
1 year	8.0 (6.3)	8.9 (5.8)	−0.8 (−2.9 to 1.2)
2 years	8.0 (6.0)	8.3 (5.7)	−0.3 (−2.3 to 1.7)
Self efficacy‡
Baseline	3.4 (1.5)	3.6 (1.6)	—
3 months	6.1 (2.3)	5.0 (2.2)	1.0 (0.2 to 1.9)
6 months	6.0 (2.6)	5.6 (2.4)	0.5 (−0.3 to 1.3)
1 year	6.4 (3.3)	5.5 (2.5)	0.9 (0.0 to 1.7)
2 years	6.2 (2.7)	5.6 (2.7)	0.5 (−1.4 to 2.8)

*See tables 1 and 5 for score details.

†EQ-5D P<0.001, HSCL P<0.001, FABQ work P=0.057, FABQ physical P=0.548, self efficacy P=0.019 for trend in treatment effect over time.

‡Positive scores indicate larger improvement in outcome with surgery.

§Negative scores indicate larger improvement in outcome with surgery.