Dr Duncan Critchley
A comparison of the effectiveness of three physiotherapy regimes commonly used to reduce disability in patients with chronic low back pain.
Background
Chronic low back pain results in considerable suffering, disability, and work-absenteeism. The annual cost of low-back pain to the NHS is estimated at £1.1 billion (1998 figures), chronic problems responsible for 80% of these costs. Exercise-based physiotherapy reduces disability in chronic back pain, but it is unclear if one form of physiotherapy is most effective or cost effective.
Methods
We carried out a pragmatic assessor-blind trial, randomly allocating 212 non-specific cLBP patients, referred for physiotherapy and able to participate in exercise classes, to usual individual physiotherapy (manual therapy and specific exercises according to assessment findings), spinal stabilisation classes (specific exercises to rehabilitate trunk muscles thought stabilise spinal segments), and physiotherapist-led pain management classes (paced, progressive, general exercises and advice/education on living with chronic pain). Treatments took place in Guy’s and St Thomas’ hospitals physiotherapy departments.
Participants were assessed at baseline and 6, 12 and 18 months (primary endpoint). Primary outcome was Roland disability index; secondary measures included pain (NAS), health-related quality of life (EQ-5D - also used to calculate QALYs), and number off-work. Adverse effects were defined as an increase in pain or symptoms within one week of treatment requiring general practitioner or casualty consultation.
Economic measures were NHS (UK public health service) costs associated with low-back pain and quality adjusted life years (QALYs) over eighteen months of trial.
Analysis
Treatments were compared according to a pre-planned data using ANCOVA with baseline as covariant on an intention-to-treat basis.
Findings
71 participants were allocated to individual physiotherapy, 72 to spinal stabilisation and 69 to pain management. 160 (75%) provided follow-up data at eighteen months. At baseline, participants were 64% female, 58% in social housing, 20% not working due to back pain, mean (SD) age 45 (12) years, duration of problem 7.4 (9.2) years.
At eighteen months, all groups’ mean (95% Confidence Intervals) Roland disability index improved significantly: from 11.1 (9.6-12.6) to 6.9 (5.3-8.4) with individual physiotherapy, 12.8 (11.4 -14.2) to 6.8 (4.9-8.6) with spinal stabilisation, and 11.5 (9.8-13.1) to 6.5 (4.5-8.6) with pain management (all P<0.001). Results at six and twelve months were similar to those at eighteen months. There were no significant between-groups differences at any outcome points. Pain, quality of life and number off-work similarly improved within all groups with no between-group differences at any outcome points. Imputing missing data using the last value carried forward method did not change these conclusions. No adverse events were reported by any participants.
Patients in the pain management arm had fewer secondary care visits, inpatient procedures, and investigations compared to patients in the individual physiotherapy and spinal stabilisation arms, contributing to markedly lower costs: Mean (SD) NHS costs and QALY gain over eighteen months were £474 (840) and 0.99 (0.27) for individual physiotherapy, £379 (1040) and 0.90 (0.37) for spinal stabilisation and £165 (202) and 1.00 (0.28) for pain management. Excluding three patients who received costly spinal surgery did not change the ‘base case’ conclusion that physiotherapist-led pain management was most cost-effective.
cLBP-related public health-service costs for all participants for 6 months prior to baseline were £169.29 (349.71), and were significantly lower for each six month period of the trial: 0-6 months =£70.49 (452.74) (P<0.001); 6-12 months =£92.14 (502.11) (P=0.003), and 12-18 months =£103.03 (535.90) (P=0.036).
Interpretation
All three physiotherapy regimens, regardless of content, improved disability and other relevant health outcomes. Improvements in disability in all arms were clinically important, observed shortly after intervention and maintained for one year. Physiotherapist-lead out-patient pain management offers a cost-effective alternative to current usual physiotherapy for chronic low back-pain requiring no special equipment or facilities. A strength of the study is the generalisability of the results: the socio-economic and ethnic profile of participants was representative of the general population in this inner-city location. Additionally, treatments were carried out in hospital departments by NHS physiotherapists not specially trained researchers. Although, for ethical reasons, there was no ‘non-intervention’ control arm, pain and disability remain almost constant once back-pain becomes chronic thus we are confident these results indicate improvements through treatment rather than the natural history of the condition.
Economic analysis is unusual in rehabilitation studies yet in this trial it reveals important differences between interventions not apparent from clinical outcomes. Mean NHS costs were £206 less per year per patient in pain management compared with individual physiotherapy, suggesting this treatment promoted more effective self-management. Conservatively, 50% of patients referred to physiotherapy were suitable for functional restoration. Extrapolating these results, if half the 1.23 million patients receiving NHS physiotherapy for back pain per year were treated within physiotherapist-lead pain management programmes instead of individually (current usual practice), savings to the NHS would be in the order of £126 million per year (2003-4 prices).
Given the prevalence of chronic low back pain and its personal and socio-economic costs these findings may have important implications for primary care management.
Acknowledgements
We thank the trial participants who volunteered considerable time to attend assessments, the physiotherapists and physiotherapy assistants who helped develop the protocol and deliver the interventions, particularly Kelly Ridley who designed and implemented the pain management programme. Caroline Dore, ARC Statistician, MRC clinical trials unit, was responsible for statistical advice, and assisted the data analysis.