Table 3.
ITT estimates of clinical effectiveness at 3, 6 and 12 months
| |
All |
Advice plus cognitive behavioural intervention |
|
|||
|---|---|---|---|---|---|---|
| |
Control |
Advice plus cognitive behavioural intervention |
Non-complier |
Complier |
Mean compliance difference (95% CI)
*
|
p value |
| Mean change from baseline (95% CI) * | Mean change from baseline (95% CI) * | |||||
|
Roland Morris Questionnaire (points)
†
| ||||||
| 3 months |
0.9 (0.32, 1.53) |
2.0 (1.55, 2.46) |
0.9 (-0.06, 1.83) |
2.3 (1.82, 2.85) |
1.5 (0.44, 2.47) |
0.005 |
| 6 months |
1.0 (0.38, 1.64) |
2.5 (1.98, 2.92) |
1.6 (0.68, 2.58) |
2.7 (2.18, 3.21) |
1.0 (-0.00, 2.07) |
0.05 |
| 12 months |
1.0 (0.36, 1.70) |
2.3 (1.86, 2.82) |
2.1 (1.12, 3.07) |
2.5 (1.99, 3.09) |
0.4 (-0.62, 1.52) |
0.41 |
|
Modified Von Korff disability (%)
†
| ||||||
| 3 months |
8.8 (5.42, 12.14) |
13.4 (10.81, 16.03) |
6.5 (1.27, 11.65) |
14.6 (11.56, 17.71) |
8.2 (2.51, 13.82) |
0.005 |
| 6 months |
5.7 (2.17, 9.19) |
14.0 (11.43, 16.60) |
9.0 (4.30, 13.67) |
15.2 (12.07, 18.42) |
6.3 (0.99, 11.53) |
0.02 |
| 12 months |
5.3 (1.82, 8.78) |
13.9 (11.32, 16.50) |
10.0 (5.48, 14.60) |
16.0 (12.88, 19.12) |
6.0 (0.78, 11.14) |
0.024 |
|
Modified Von Korff pain (%)
†
| ||||||
| 3 months |
5.4 (2.41, 8.30) |
12.3 (10.02, 14.51) |
7.4 (2.85, 11.87) |
13.6 (10.94, 16.22) |
6.2 (1.31, 11.12) |
0.013 |
| 6 months |
5.6 (2.27, 8.85) |
13.8 (11.38, 16.18) |
8.8 (4.44, 13.24) |
15.5 (12.51, 18.41) |
6.6 (1.67, 11.58) |
0.009 |
| 12 months |
6.4 (3.12, 9.62) |
13.4 (10.98, 15.76) |
11.6 (7.28, 15.85) |
14.4 (11.52, 17.21) |
2.8 (-2.05, 7.65) |
0.257 |
|
EQ-5D | ||||||
| 3 months |
0.5 (0.51, 0.58) |
0.6 (0.59, 0.65) |
0.6 (0.50, 0.61) |
0.6 (0.59, 0.66) |
0.1 (0.01, 0.13) |
0.014 |
| 6 months |
0.6 (0.54, 0.62) |
0.6 (0.59, 0.65) |
0.6 (0.55, 0.64) |
0.6 (0.60, 0.66) |
0.03 (-0.03, 0.09) |
0.293 |
| 12 months | 0.6 (0.54, 0.61) | 0.6 (0.60, 0.66) | 0.6 (0.56, 0.66) | 0.6 (0.59, 0.66) | 0.01 (-0.04, 0.07) | 0.616 |
Estimates of disability, pain and health related quality of life at 3, 6 and 12 months for all participants (ITT) and for compliers and non-compliers in the advice plus cognitive behavioural intervention arm with the difference between compliers and non-compliers.
Participants in the control group were assigned to receive advice only.
*Based on a linear regression model adjusted for age, sex, severity of back pain, centre and baseline value.
†The number of participants used in the regression analyses differs for each month on each score; due to missing data in the outcome and predictors.