Table 1 Baseline variables

Dependent variables

Back + leg pain intensity^a , mean (SD) (range)

32.3 (11.9) (8, 60)

 Women, mean (SD)

32.4 (12.3)

 Men, mean (SD)

32.1 (11.6)

Back pain intensity^a, mean (SD) (range)

17.7 (6.50) (3, 30)

 Women, mean (SD)

18.6 (5.8)

 Men, mean (SD)

16.6 (7.1)

Leg pain intensity^a, mean (SD) (range)

14.4 (8.30) (0, 30)

 Women, mean (SD)

13.6 (8.5)

 Men, mean (SD)

15.3 (8.0)

Independent variables

MRI findings (presented in Table 2)

Demographic and clinical variables

Sex: female/all (% female)

75/141 (53)

Age: mean (SD) (range)

41.6 (10.6) (18–60)

Body Mass Index (BMI): mean (SD) (range)

26.8 (4.55) (18.4–40.2)

N^o with radiculopathy/all, n (%)

61/141 (43)

Disability (Roland Morris), mean (SD) (range)

15.7 (3.8) (5–23)

 Women, mean (SD)

15.6 (4.0)

 Men, mean (SD)

15.8 (3.6)

Duration of pain, n (%)

  ≤ 3 mo

73 (53)

 3-6 mo

38 (27)

 7-12 mo

9 (7)

  > 12 mo

18 (13)

Much bothered by widespread pain the preceding 2 wk/all , n (%)

23/141 (16)

Using pain medicine 5–7 days pr. wk/ 0–4 days pr. wk/all

86/50/135

Tender points: median (range)

6 (0–18)