Table 5 Participant-reported secondary outcome measures

Low back disability (Roland Morris) [0 to 100; lower scores indicate less disability]

Mean at baseline (SD)

40.9 (21.3)

38.1 (19.2)

Mean at week 4 (95% CI)

30.3 (27 to 33.6)

27.0 (23.7 to 30.2)

3.07 (− 0.95 to 7.08)

Mean at week 12 (95% CI)

19.9 (16.6 to 23.2)

16.5 (13.3 to 19.7)

3.66 (− 0.65 to 7.97)

Short term response summary (area under the curve minus baseline through week 12)

3.36 (− 0.65 to 7.38)

Mean at week 26 (95% CI)

24.6 (21.2 to 27.9)

20.2 (16.9 to 23.4)

4.05 (− 0.97 to 9.07)

Mean at week 52 (95% CI)

25.6 (22.1 to 29)

19.0 (15.7 to 22.3)

6.54 (1.18 to 11.90)

Long term response summary (area under the curve minus baseline through week 52)

4.62 (0.88 to 8.36)

Improvement [1 to 9; 1 = 100% Improvement, 9 = 100% Worse]

Mean at week 4 (95% CI)

3.9 (3.6 to 4.1)

3.6 (3.3 to 3.8)

0.31 (0.03, 0.60)

Mean at week 12 (95% CI)

3.1 (2.9 to 3.4)

2.8 (2.6 to 3.1)

0.29 (− 0.04, 0.63)

Short term response summary

(Area under the curve through week 12)

0.31 (0.01 to 0.61)

Mean at week 26 (95% CI)

3.5 (3.2 to 3.8)

3.1 (2.8 to 3.3)

0.38 (0.08, 0.68)

Mean at week 52 (95% CI)

3.6 (3.3 to 3.9)

3.1 (2.8 to 3.3)

0.37 (0.08, 0.65)

Long term response summary (area under the curve through week 52)

0.41 (0.14 to 0.68)

Medication use [days/week]

Mean at baseline (SD)

2.8 (2.4)

2.9 (2.4)

Mean at week 4 (95% CI)

2.3 (1.9 to 2.7)

2.6 (2.2 to 3)

− 0.27 (− 0.77 to 0.24)

Mean at week 12 (95% CI)

1.8 (1.4 to 2.2)

1.8 (1.4 to 2.2)

− 0.05 (− 0.63 to 0.52)

Short term response summary (area under the curve minus baseline through week 12)

− 0.21 (− 0.71 to 0.30)

Mean at week 26 (95% CI)

1.8 (1.4 to 2.2)

2.2 (1.8 to 2.6)

− 0.44 (− 1.06 to 0.19)

Mean at week 52 (95% CI)

2.3 (1.9 to 2.8)

1.9 (1.5 to 2.4)

0.50 (− 0.17 to 1.17)

Long term response summary (area under the curve minus baseline through week 52)

− 0.11 (− 0.58 to 0.36)

Quality of life (EuroQol) [− 0.109 to 1; higher scores indicate better quality of life]

Mean at baseline (SD)

0.76 (0.10)

0.79 (0.06)

Mean at week 4 (95% CI)

0.80 (0.78 to 0.82)

0.81 (0.79 to 0.83)

− 0.01 (− 0.04 to 0.02)

Mean at week 12 (95% CI)

0.83 (0.81 to 0.85)

0.85 (0.83 to 0.87)

− 0.02 (− 0.05 to 0.01)

Short term response summary (area under the curve minus baseline through week 12)

− 0.01 (− 0.04 to 0.01)

Mean at week 26 (95% CI)

0.81 (0.79 to 0.83)

0.82 (0.80 to 0.84)

− 0.02 (− 0.04 to 0.01)

Mean at week 52 (95% CI)

0.82 (0.79 to 0.84)

0.84 (0.82 to 0.86)

− 0.02 (− 0.05 to 0.004)

Long term response summary (area under the curve minus baseline through week 52)

− 0.02 (− 0.04 to 0.003)

Satisfaction with care [1 to 7; 1 = Completely Satisfied, 7 = Completely Dissatisfied]

Mean at week 4 (95% CI)

2.1 (1.9 to 2.3)

1.8 (1.6 to 2)

0.34 (0.12, 0.57)

Mean at week 12 (95% CI)

2 (1.8 to 2.2)

1.7 (1.5 to 1.9)

0.33 (0.09, 0.56)

Short term response summary (area under the curve minus baseline through week 12)

0.34 (0.11 to 0.56)

Mean at week 26 (95% CI)

2.3 (2.1 to 2.5)

1.9 (1.7 to 2.1)

0.38 (0.08, 0.68)

Mean at week 52 (95% CI)

2.2 (2 to 2.4)

1.8 (1.6 to 2)

0.37 (0.08, 0.65)

Long term response summary (area under the curve through week 52)

0.38 (0.16 to 0.59)

Low back symptom frequency [0 to 5; 0 = none of the time, 5 = all of the time]

Mean at baseline (SD)

Mean at week 4 (95% CI)

3.11 (2.9 to 3.32)

2.83 (2.62 to 3.04)

0.28 (− 0.01 to 0.58)

Mean at week 12 (95% CI)

2.38 (2.17 to 2.59)

2.02 (1.81 to 2.23)

0.36 (0.06 to 0.66)

Short term response summary

(Area under the curve minus baseline through week 12)

0.31 (0.07 to 0.56)

Mean at week 26 (95% CI)

2.68 (2.47 to 2.9)

2.33 (2.12 to 2.54)

0.35 (0.05 to 0.66)

Mean at week 52 (95% CI)

2.41 (2.19 to 2.64)

1.95 (1.74 to 2.16)

0.46 (0.16 to 0.77)

Long term response summary (area under the curve through week 52)

0.38 (0.15 to 0.60)

Leg symptom frequency [0 to 5; 0 = none of the time, 5 = all of the time]

Mean at baseline (SD)

Mean at week 4 (95% CI)

1.1 (0.92 to 1.28)

1.03 (0.85 to 1.21)

0.07 (− 0.19 to 0.32)

Mean at week 12 (95% CI)

0.77 (0.58 to 0.95)

0.66 (0.49 to 0.84)

0.1 (− 0.15 to 0.36)

Short term response summary

(Area under the curve minus baseline through week 12)

0.08 (− 0.13 to 0.29)

Mean at week 26 (95% CI)

0.94 (0.75 to 1.12)

0.87 (0.69 to 1.05)

0.07 (− 0.2 to 0.33)

Mean at week 52 (95% CI)

1.04 (0.85 to 1.24)

0.79 (0.6 to 0.97)

0.26 (− 0.01 to 0.52)

Long term response summary

(Area under the curve through week 52)

0.12 (− 0.06 to 0.31)

Any missed work days due to back problem in past month [%]

Percentage at baseline (n)

36.3 (36)

36.6 (37)

Percentage at week 4 (95% CI)

23.5 (16.4 to 30.5)

24.2 (17.4 to 31.0)

− 0.7 (− 10.2 to 8.7)

Percentage at week 12 (95% CI)

17.5 (11.0 to 24.1)

13.0 (8.2 to 17.8)

4.5 (− 3.1 to 12.1)

Percentage at week 26 (95% CI)

15.2 (9.4 to 21.1)

16.6 (10.6 to 22.6)

− 1.3 (− 9.1 to 6.5)

Percentage at week 52 (95% CI)

17.3 (10.5 to 24.1)

16.1 (9.9 to 22.3)

1.2 (− 7.6 to 10.0)

Number of missed work days due to back problem in past month [0–31 days]

Mean at baseline (SD)

6.0 (4.9)

6.6 (6.8)

Mean at week 4 (95% CI)

6.09 (3.56 to 8.62)

4.49 (3.13 to 5.85)

1.60 (− 1.29 to 4.49)

Mean at week 12 (95% CI)

2.18 (1.35 to 3.01)

3.84 (1.55 to 6.12)

− 1.65 (− 4.12 to 0.81)

Mean at week 26 (95% CI)

6.23 (1.33 to 11.14)

5.38 (0.54 to 10.21)

0.86 (− 6.07 to 7.78)

Mean at week 52 (95% CI)

3.16 (1.98 to 4.33)

6.11 (0.20 to 12.02)

− 2.96 (− 9.03 to 3.11)

Any reduced activity days due to back problem in past month [%]

Percentage at baseline (n)

74.0 (74)

72.2 (73)

Percentage at week 4 (95% CI)

54.4 (45.7 to 63.1)

64.8 (56.5 to 73.1)

− 10.4 (− 22.4 to 1.6)

Percentage at week 12 (95% CI)

41.3 (31.4 to 51.2)

41.8 (32.9 to 50.8)

− 0.6 (− 13.9 to 12.8)

Percentage at week 26 (95% CI)

43.7 (34.7 to 52.7)

37.1 (30.0 to 44.2)

6.6 (− 4.4 to 17.6)

Percentage at week 52 (95% CI)

41.5 (32.6 to 50.4)

34.7 (26.9 to 42.5)

6.8 (− 4.5 to 18.2)

Number of reduced activity days due to back problem in past month [0–31 days]

Mean at baseline (SD)

9.0 (8.2)

8.4 (8.0)

Mean at week 4 (95% CI)

6.05 (5.02 to 7.08)

5.07 (4.19 to 5.95)

0.98 (− 0.26 to 3.01)

Mean at week 12 (95% CI)

5.04 (3.10 to 6.99)

4.22 (3.10 to 5.35)

0.82 (− 1.37 to 3.01)

Mean at week 26 (95% CI)

4.58 (3.56 to 5.60)

4.53 (3.55 to 5.51)

0.05 (− 1.24 to 1.33)

Mean at week 52 (95% CI)

4.84 (3.36 to 6.33)

4.53 (3.54 to 5.52)

0.31 (− 1.34 to 1.96)

Fear avoidance beliefs—work subscale [0–42; higher scores indicate greater fear avoidance beliefs]

Mean at baseline (SD)

9.13 (8.94)

9.69 (8.47)

Mean at week 4 (95% CI)

8.30 (7.15 to 9.45)

7.53 (6.4 to 8.66)

0.77 (− 0.84 to 2.38)

Mean at week 12 (95% CI)

7.10 (5.94 to 8.26)

5.94 (4.82 to 7.06)

1.16 (− 0.45 to 2.77)

Short term response summary (area under the curve minus baseline through week 12)

0.93 (− 0.46 to 2.31)

Mean at week 26 (95% CI)

6.80 (5.62 to 7.98)

5.65 (4.51 to 6.78)

1.15 (− 0.48 to 2.79)

Mean at week 52 (95% CI)

6.60 (5.39 to 7.81)

6.49 (5.34 to 7.64)

0.11 (− 1.56 to 1.78)

Long term response summary (area under the curve through week 52)

0.84 (− 0.44 to 2.11)

Fear avoidance beliefs—physical activity subscale [0 to 24; higher scores indicate greater fear avoidance beliefs]

Mean at baseline (SD)

11.66 (5.42)

11.63 (5.32)

Mean at week 4 (95% CI)

9.03 (8.04 to 10.01)

9.3 (8.33 to 10.27)

− 0.28 (− 1.66 to 1.11)

Mean at week 12 (95% CI)

7.54 (6.55 to 8.54)

7.36 (6.39 to 8.33)

0.18 (− 1.21 to 1.57)

Short term response summary

(Area under the curve minus baseline through week 12)

− 0.09 (− 1.31 to 1.12)

Mean at week 26 (95% CI)

7.71 (6.7 to 8.72)

6.52 (5.53 to 7.5)

1.20 (− 0.21 to 2.6)

Mean at week 52 (95% CI)

7.61 (6.57 to 8.64)

7.22 (6.23 to 8.21)

0.39 (− 1.04 to 1.82)

Long term response summary (area under the curve through week 52)

0.59 (− 0.55 to 1.72)

Self-efficacy [0 to 60; higher scores indicate greater self-efficacy]

Mean at baseline (SD)

48.0 (10.0)

49.2 (8.7)

Mean at week 4 (95% CI)

52.2 (50.9 to 53.6)

52 (50.7 to 53.4)

0.18 (− 1.70 to 2.07)

Mean at week 12 (95% CI)

54.4 (53 to 55.7)

54.7 (53.4 to 56)

− 0.33 (− 2.22 to 1.57)

Short term response summary (area under the curve minus baseline through week 12)

− 0.02 (− 1.67 to 1.63)

Mean at week 26 (95% CI)

52.5 (51.2 to 53.9)

53.2 (51.8 to 54.5)

− 0.63 (− 2.55 to 1.29)

Mean at week 52 (95% CI)

51.8 (50.4 to 53.2)

53.8 (52.5 to 55.2)

− 1.99 (− 3.94 to − 0.04)

Long term response summary (area under the curve through week 52)

− 0.82 (− 2.35 to 0.71)

Active pain coping strategies (pain management inventory) [5 to 25; higher scores indicate more frequent use]

Mean at baseline (SD)

17.3 (3.4)

17.1 (3.6)

Mean at week 12 (95% CI)

18.2 (17.6 to 18.9)

19.0 (18.4 to 19.7)

− 0.8 (− 1.7 to 0.1)

Passive pain coping strategies (Pain Management Inventory) [6 to 30; higher scores indicate more frequent use]

Mean at baseline (SD)

13.8 (4.5)

13.9 (3.9)

Mean at week 12 (95% CI)

12.6 (12.0 to 13.2)

11.7 (11.1 to 12.3)

0.9 (0.1 to 1.7)

Kinesiophobia [17 to 68] (11 questions; 1 = Strongly Disagree—4 = Strongly Agree)

Mean at baseline (SD)

35.2 (6.3)

33.2 (5.8)

Mean at week 12 (95% CI)

29.7 (28.6 to 30.8)

28.7 (27.6 to 29.8)

1.0 (2.6 to − 0.6)