A multicentred randomised controlled trial of a primary care-based cognitive behavioural programme for low back pain: the Back Skills Training (BeST) trial

Citation

(2011), "A multicentred randomised controlled trial of a primary care-based cognitive behavioural programme for low back pain: the Back Skills Training (BeST) trial", Clinical Governance: An International Journal, Vol. 16 No. 1. https://doi.org/10.1108/cgij.2011.24816aaf.002

A multicentred randomised controlled trial of a primary care-based cognitive behavioural programme for low back pain: the Back Skills Training (BeST) trial

Article Type: Health technology assessment From: Clinical Governance: An International Journal, Volume 16, Issue 1

S.E. Lamb, R. Lall, Z. Hansen, E. Castelnuovo, E.J. Withers, V. Nichols, F. Griffiths, R. Potter, A. Szczepura and M. Underwood, on behalf of the BeST trial group

Background

Low back pain (LBP) is a common and costly problem for which cognitive behavioural approaches may be effective.

Design

A randomised controlled trial was undertaken with a parallel economic and qualitative evaluation comparing active management (AM) with AM plus group treatment using a cognitive behavioural approach (CBA). We randomised individuals using a stratified unbalanced randomisation (2:1 in favour of the CBA arm).

Setting

A total of 56 general practices were recruited from seven English regions.

Control intervention

Primary-care nurses attended a one-hour training session on the management of LBP, focusing on internationally accepted best practice recommendations for primary care to promote physical activity and analgesia, and to encourage a positive outlook. Nurses were asked to cascade this information within their general practices, and to see each trial participant for an individual advisory session promoting this approach. The advisory session was supplemented with a copy of The Back Book, which was designed by experts in LBP, to reinforce the messages described above.

Intervention (cognitive behavioural approach) arm

Physiotherapists, nurses, psychologists and occupational therapists delivered a simple cognitive behavioural formulation that was tailored for LBP, and designed to target unhelpful beliefs about pain and activity, and promote engagement in leisure, physical and occupational activity. Therapists attended a two-day training course and were supported with remote mentorship. The intervention was structured and standardised using a treatment manual for both therapists and participants. Each participant attended for an individualised assessment that included goal setting. Thereafter, the CBA intervention was delivered in groups, with approximately eight people starting each cycle. The contents of the group sessions included goal setting, pacing, challenging beliefs, managing pain and improving communication with health professionals. We defined compliance as attending the assessment and at least three of the six group sessions.

Recruitment

We identified potential participants by searching electronic general practice records, and from direct referrals from general practitioners. Each potential participant went through a two-stage eligibility check to ensure they had at least moderately troublesome back pain present for at least 6 weeks and to exclude those with a serious disorder causing their LBP.

Follow-up

We collected follow-up data at three, six and 12 months. The primary method of data capture was postal questionnaire. This was supplemented with telephone data collection for individuals who did not return a questionnaire but were happy to provide information.

Clinical outcomes and analysis

The primary outcomes were the Roland Morris disability questionnaire (RMQ) and the modified Von Korff (MVK) scale, which measure LBP and disability. Secondary outcomes included mental and physical health-related quality of life (Short Form 12-item health survey; SF-12), health status, fear avoidance beliefs and pain self-efficacy. The planned sample size was 700. We analysed the difference in change from baseline scores at each time point, and also analysed these over time to yield a single summary score. We used a linear regression model for the analysis, as the clustering effects (therapist and groups) were found to be non-significant. Models were adjusted for age, sex and baseline covariates. Subgroup analyses were prespecified for fear avoidance beliefs, and the severity and duration of LBP.

Economic analysis

We considered the cost-utility of the CBA programme from both the UK NHS perspective and a broader health-care perspective. We included all NHS costs needed to deliver the interventions and to provide health care associated with LBP over a 12-month time horizon. For the health-care perspective we included both NHS costs and costs of privately purchased goods and services related to LBP. Quality-adjusted life-years (QALYs) were calculated from the EuroQoL five dimensions. We collected cost data from participant questionnaires. Costs were in UK pounds (£) actualised to 2008 using the retail price index. Discounting was not applied.

Results

Between April 2005 and April 2007 we randomised 701 participants who provided baseline data; 233 were randomised to best care (AM) and 468 to best care (AM)+CBA. Nearly 60 per cent (420/701) were female, mean age of participants was 54 [standard deviation (SD) 14.9] years and mean baseline RMQ was 8.7 (SD 4.9). Outcome data were obtained for 85 per cent of participants at 12 months.

Benefits were seen across the range of outcome measures in favour of CBA. There was no evidence of group or therapist effects. Both treatments showed improvements over baseline, but these were of a different magnitude and time course. Overall, CBA resulted in at least twice as much improvement as AM and, for the primary outcomes; improvements were sustained or increased over time. Mean additional improvement in the CBA arm was 1.1 [95 per cent confidence interval (CI) 0.4 to 1.7], 1.4 (95 per cent CI 0.7 to 2.1) and 1.3 (95 per cent CI 0.6 to 2.1) change points in the RMQ at 3, 6 and 12 months respectively. Additional improvement in MVK (pain) was 6.8 (95 per cent CI 3.5 to 10.2), 8.0 (95 per cent CI 4.3 to 11.7) and 7.0 points (95 per cent CI 3.2 to 10.7) at 3, 6 and 12 months. For MVK (disability), additional improvements were 4.3 (95 per cent CI 0.4 to 8.2), 8.1 (95 per cent CI 4.1 to 12.0) and 8.4 points (95 per cent CI 4.4 to 12.4) at 3, 6 and 12 months. All differences in the primary outcomes at 6 and 12 months were statistically significant. Differences in physical health-related quality of life and intermediary outcomes were substantial. At 12 months, the treatment effect size was 0.31, 0.41 and 0.45 for the RMQ, MVK and SF-12 physical health scales respectively. At the same time point, 60 per cent of the CBA arm and 31 per cent of the AM arm reported some or complete recovery.

Economics

The mean cost of attending a CBA course was £187 per participant, which accounted almost entirely for the average difference in NHS costs between the AM and AM+CBA arms (£224.65 versus £421.52). CBA resulted in an additional benefit in QALYs of 0.099 and an additional cost of £178.06. The incremental cost-effectiveness ratio was £1,786.00. The probability of CBA being cost-effective reached 90 per cent at about £3,000 and remained at that level or higher above that threshold. At a cost-effectiveness threshold of £20,000 group CBA had an almost 100 per cent probability of being considered cost-effective. The cost per QALY was similar in all sensitivity and prespecified subgroup analyses. From the participant perspective CBA resulted, on average, in an additional £130 of out-of-pocket expenses, increasing cost per QALY to £3,093.

Qualitative study

We explored user perspectives on the acceptability of group treatments and sought insights into how the intervention might work. Semi-structured interviews were completed in a purposive sample of 34 trial participants (AM=18, AM+CBA=16). Almost everyone was familiar with the key messages of the AM approach, although they had not previously received a copy of The Back Book. Most of those who had attended any group sessions had retained key messages from the sessions and two-thirds talked about a reduction in fear avoidance and changes in their behaviour. Most also found the exercises helpful and had incorporated exercise into their daily lives. Different individuals reported different strategies included in the CBA package to be helpful. Several people mentioned the importance of the assessment session. Group sessions appear to provide reassurance, to lessen isolation and to enable participants to learn strategies from each other.

Conclusions

This definitive large-scale randomised controlled trial has demonstrated the long-term effectiveness and cost-effectiveness of CBA in treating subacute and chronic LBP. The clinical effectiveness and cost-effectiveness outcomes are likely to make this intervention attractive to patients, clinicians and purchasers. Our short-term (three-month) clinical effects are similar to those found in high-quality studies of other therapies such as manipulation, acupuncture or exercise. Strikingly, and in contrast to many previous studies, the benefits we observed were maintained and increased over the long term (12 months). The intervention is extremely cost-effective from an NHS and a health-care perspective; cost per QALY is less than or about half that of competing interventions for LBP. Finally, because the intervention can be delivered by existing NHS staff following a brief, two-day training session, the back skills training programme could be implemented into the NHS with relative ease.

Future research questions

Future research on implementation of the CBA programme will help to ensure that the benefits we found can be translated into a reduction in LBP and associated disability. Further work is needed to examine alternative strategies to delivery, particularly where these improve patient choice and ability to either attend the sessions or gain the cognitive skills and behavioural stimulus embedded in the approach. Some evidence that CBA may also be of help for other musculoskeletal disorders is given by the effects of the package on generalised physical health-related quality of life. Extended follow-up of the BeST cohort may provide additional useful information on the sustainability of clinical effectiveness and cost-effectiveness, and guide the development of brief interventions to help maintain effects over much longer time periods.

Trial registration

This trial is registered as ISRCTN37807450.

© 2010 Crown Copyright

S.E. Lamb, R. Lall, Z. Hansen, E.J. Withers, V. Nichols, F. Griffiths, R. Potter, and M. Underwood are all based at the Warwick Trials Unit, Warwick Medical School, University of Warwick, Coventry, UK.

E. Castelnuovo is based at the Centre for Health Economics, University of York, York, UK.

A. Szczepura is Health Sciences Research Institute, Warwick Medical School, University of Warwick, Coventry, UK.