Table 1 Characteristics of the Study Sample; the Whole Sample (n = 90) and the Sub-group Participating in Test-retest (n = 60)

Age (yrs.)

47.6 (11.7)

49.2 (11.2)

Sex (% Women)

52 (58%)

32 (52%)

Born in Norway (% yes)

80 (89%)

58 (95%)

Civil status

Single

21 (23%)

15 (25%)

Married/cohabiting

69 (77%)

46 (75%)

Work status

Employed

40 (44%)

24 (39%)

Sick-listed

18 (20%)

15 (25%)

Pension (disability, retired)

25 (28%)

18 (30%)

Pain localization

Lower back only

32 (36%)

23 (38%)

Lower back and other sites

57 (63%)

38 (62%)

Pain duration

Less than 3 months

19 (21%)

11 (18%)

3 months or more

71 (79%)

50 (82%)

Pain duration (yrs.)

9.7 (13.2)

11.0 (13.3)

Back pain Numeric Rating Scale (0–10)

4.8 (2.1)

4.9 (2.1)

Pain Catastrophizing Scale total score (0–52)

13.6 (9.2)

13.6 (8.9)

Roland Morris Disability Questionnaire (0–24)

7.6 (5.2)

7.2 (5.1)

Core Outcome Measure Index (0–10)

5.6 (1.9)

5.6 (1.8)

Fear Avoidance Beliefs Questionnaire, Physical Activity (0–24)

9.4 (5.5)

8.8 (5.3)

Fear Avoidance Beliefs Questionnaire, Work (0–42)

16.7 (11.9)

17.0 (11.2)

Hopkins Symptom Check List-25 (1–4)

1.61 (0.49)

1.64 (0.49)

EQ-5D

0.54 (0.31)

0.55 (0.29)