Table 2 Patient characteristics at baseline

Age (mean (SD))

41.0 (7.2)

41.6 (7.1)

Gender (women (n %))

77 (52.4)

65 (51.6)

BMI (mean (SD))

25.3 (3.2)

25.4 (3.2)

Current smoker (n % yes)

66 (44.9)

58 (46.0)

Previous back surgery (n % yes)^a

44 (29.9)

37 (29.4)

Work status ^b (n % working)

31 (21.1)

25 (19.8)

Duration of back pain, years (mean (SD))

6.3 (5.9)

6.5 (6.1)

Daily consumption of opioids (n % yes)

34 (23.1)

30 (23.8)

ODI score, 0-100^c (mean (SD))

42.3 (9.0)

41.8 (8.4)

EQ-5D index, -0.59–1^d (mean (SD))

0.28 (0.30)

0.28 (0.30)

HSCL-25, 1-4^c (mean (SD))

1.80 (0.51)

1.81 (0.50)

FABQ-physical, 0-24^c (mean (SD))

13.2 (5.6)

13.3 (5.4)

FABQ-work, 0-42^c (mean (SD))

26.5 (10.6)

26.0 (10.4)

Back Pain, 0-100^c (mean (SD))

70.0 (14.9)

69.4 (15.0)

Leg Pain, 0-100^c (mean (SD))

44.5 (26.8)

47.0 (25.7)