Lay-tutors in a back school programme
Table II. Baseline characteristics of 87 patients included in the study
Referred from general
practitioners and specialists
n = 117
Excluded
n = 30
Refused to
participate
Randomised
n = 87
Lost to follow-up
n = 2
Reason: did not
answer the second
guestionnaire
Allocated to
intervention group
n = 42
Received allocated
intervention Allocated to
control group
n = 45
Received allocated
intervention
Analysed
n = 40
3 months follow-up Analysed
n = 42
3 months follow-up
Lost to follow-up
n = 3
Reason: did not
answer the second
guestionnaire
Lost to follow-up
n = 6
Reason: did not
answer the third
guestionnaire
Lost to follow-up
n = 3
Reason: did not
answer the third
guestionnaire
Analysed
n = 37
24 months follow-up
701
Analysed
n = 36
24 months follow-up
Fig. 1. Recruitment and participation in the study.
up, and 73 patients (84%) responded at the 24-month
follow-up (Fig. 1). Similar dropouts occurred for both
study groups with regard to age and sex.
Table II presents the baseline characteristics of the
participants. Overall, the 2 groups were comparable
in terms of baseline characteristics, including demo-
graphic characteristics, employment status, duration
of pain, number of back episodes and sick leave. The
2 groups were also comparable at baseline in terms of
the different outcome measures, RMQ, back pain, leg
pain and SF-36 (Table III).
With regard to the primary outcome measure, the
RMQ scores for functional activity, the mean score at
Variables Intervention Control
group
group
( n = 42)
( n =45)
Sex, female, n (%)
Age, years, mean (SD) 22 (52)
48 (9.5) 24 (53)
46 (8.6)
25 (3.7)
38 (90)
19 (45) 25 (3.9)
33 (73)
22 (49)
1 (2)
3 (7)
25 (60)
4 (10)
9 (21) 2 (7)
2 (4)
31 (69)
3 (7)
3 (13)
42 (100)
0
0 42 (93)
2 (5)
1 (2)
29 (69) 27 (60)
Body mass index, kg/m 2 , mean (SD)
Married/living with partner, n (%)
Children living at home, n (%)
Employment status, n (%)
Specialist worker, unskilled
Skilled
White-collar/public servant
Self-employed
Other
Duration of actual episode of low back pain, n (%)
4–12 weeks
13–24 weeks
> 24 weeks
Previous episodes of low back pain in the past 12
months, n (%)
SD: standard deviation.
baseline was 10 (95% confidence interval (95% CI)
8; 12) in the intervention group and 9 (95% CI 9; 11)
in the control group, on a 0–24-point scale, where 0
represented no disability. No statistically significant
between-group effect was found over time (Table III).
As shown in Table III, small and statistically insignifi-
cant between-group differences were found over time
when comparing the secondary outcome measures,
back pain, leg pain and general health (SF-36).
Participants in the 2 groups showed similar atten-
dance at the back school sessions. Out of the 20 back
school sessions, the median number of sessions atten-
ded by participants was 17 (25 th –75 th percentile 15; 19)
in the intervention group and 17 (25 th –75 th percentile
14; 19) in the control group.
Table III. Data on disability measured by Roland Morris Questionnaire, back pain, leg pain and general health (measured by Short Form
36 Health Survey (SF-36)) for the intervention group and the control group at all measurement times. Data are described by mean and
95% confidence intervals (95% CI). The overall between-group effects are analysed based on the intention to treat principle in a mixed
effect model for repeated measurements with group and time as systematic factors and patients as random effects
Baseline
Mean (95% CI)
Roland Morris Questionnaire Intervention group
Control group
Current back pain Intervention group
Control group
Worst back pain (14 days)
10 (8; 12)
9 (8; 11)
4 weeks
Mean (95% CI)
3 months
Mean (95% CI)
2 years
Mean (95% CI)
Between-group
effects over time
Mean (95% CI)
6 (4; 8)
7 (5; 9) 6 (5; 8)
6 (4; 7) 7 (5; 8)
7 (6; 8)
–0.2 (–2.0; 1.5)
3.9 (3.2; 4.6)
3.2 (2.5; 3.8) 2.5 (1.7; 3.2)
2.7 (1.9; 3.4) 2.4 (1.7; 3.2)
2.3 (1.7; 3.0) 2.1 (1.5; 2.7)
1.5 (0.9; 2.2) Intervention group
Control group 5.3 (4.4; 6.1)
5.4 (4.6; 6.2) 3.1 (4.4; 6.1)
3.7 (2.7; 4.6) 2.9 (2.0; 3.8)
3.6 (2.6; 4.5) 3.5 (4.6; 6.2)
3.8 (2.8; 4.7) Current leg pain Intervention group
Control group 2.0 (1.3; 2.6)
1.6 (1.0; 2.2) 1.3 (0.6; 1.9)
0.9 (0.3; 1.5) 1.2 (0.6; 1.8)
0.9 (0.3; 1.5) 1.0 (0.4; 1.5)
0.7 (0.2; 1.3) Worst leg pain (14 days) Intervention group
Control group 3.4 (2.5; 4.3)
3.1 (2.2; 4.0) 2.2 (1.4; 3.1)
1.7 (0.8; 2.5) 2.2 (1.4; 3.0)
1.5 (0.8; 2.3) 1.8 (1.0; 2.6)
1.5 (0.7; 2.3) SF-36 Physical Component score Intervention group
Control group 39.4 (37.0; 41.9)
40.5 (38.1; 42.9) 45.8 (43.2; 48.5)
44.6 (42.1; 47.1) 45.6 (42.8; 48.5)
45.3 (42.6; 48.0) 47.1 (44.6; 49.6)
46.4 (44.0; 48.9) SF-36 Mental Component score Intervention group 51.4 (48.8; 54.0) 55.7 (53.3; 58.1) 56.5 (54.0; 59.0) 55.0 (52.7; 57.2) SF-36 Physical Function Control group
Intervention group 50.2 (47.7; 52.7)
71.5 (66.5; 76.6) 53.1 (50.8; 55.4)
82.6 (77.1; 88.1) 53.2 (50.8; 55.6)
81.3 (75.9; 86.7) 54.1 (51.9; 56.3)
84.0 (79.8; 88.1) p-value = 0.20
0.03 (–5.6; 5.7)
SF-36 General Health Control group
Intervention group 73.0 (68.1; 77.9)
66.3 (60.6; 72.1) 78.4 (73.1; 83.7)
71.6 (66.0; 77.3) 79.9 (74.7; 85.1)
70.4 (64.3; 76.5) 82.9 (78.8; 87.0)
70.9 (65.3; 76.5) p-value = 0.99
1.4 (–5.8; 8.6)
Control group 68.0 (62.4; 73.5) 72.0 (66.5; 77.5) 73.0 (67.1; 78.9) 73.7 (68.1; 79.2) p-value = 0.70
p-value = 0.81
–0.5 (–1.3; 0.3)
p-value = 0.65
0.2 (–0.9; 1.3)
p-value = 0.74
–0.3 (–1.0; 0.4)
p-value = 0.38
–0.4 (–1.4: 0.5)
p-value=0.34
–0.1 (–3.1; 2.8)
p-value = 0.94
–1.7 (–4.3; 0.9)
J Rehabil Med 51, 2019