Exercise is a common treatment approach for chronic low back pain. This Cochrane review is quite large. How much evidence was able to be included?

There are a large number of trials investigating the effectiveness of exercise treatments for chronic low back pain.

This is one of the largest systematic reviews in the Cochrane Library, including 249 trials and 24 486 study participants.

Did your Cochrane review find that exercise is an effective treatment for chronic low back pain?

We did find that exercise treatments, considered together, are effective in treating people with chronic low back pain.

Our Cochrane review found that people receiving exercise treatment rated their pain on average 15 points better on a scale of 0 to 100 compared to people who had no treatment or usual care.

We consider this amount of improvement in pain intensity to be ‘clinically important’, meaning it is an amount of improvement that matters to patients.

We also synthesised evidence about functional limitation outcomes and found a consistent, small improvement in this outcome, on average 7 points on a scale of 0 to 100, for people receiving exercise treatment compared to those who received no treatment or usual care.

This did not meet our predefined minimal clinically important difference; however, it is probably still meaningful to patients.

Did the Cochrane review also examine specific types of exercise?

The objective of the Cochrane review was to use rigorous, systematic review methods to assess the impact of exercise treatments overall compared to no treatment or usual care and compared to other conservative treatments.

‘Exercise’ includes a very heterogeneous set of interventions; however, the broad question considering the treatment approach overall is relevant to many stakeholders.

The components of an exercise type that are effective (the mechanisms) are likely the same for many exercise types.

However, we know that healthcare providers who deliver exercise treatments are more interested in knowing about the evidence for specific types of exercises.

Jill Hayden's research investigates the effectiveness of exercise in the treatment of chronic low back pain. 

The type of analyses required to answer this comparative effectiveness question is not typically part of traditional meta-analyses, which only compare two treatments at one time and are not able to use full data from trials with multiple treatment groups or comparing different types of exercise treatments.

Questions comparing several different types of treatments are best answered with network meta-analysis, also called multiple treatment meta-analysis.

This network meta-analysis approach can synthesise evidence about the effectiveness of different types of exercise treatments compared to each other while also accounting for other treatment design and delivery characteristics.

Your companion paper in Journal of Physiotherapy reports that meta-analysis. Was it able to include a similarly large amount of data?

The network meta-analysis takes advantage of the rigour of the systematic review search, screening and data collection of the Cochrane review.

We were able to synthesise evidence from 217 trials that provided sufficient data; this included 507 treatment groups (369 exercise groups and 138 comparison groups), with 20 969 participants with chronic low back pain.

This provided a very robust dataset with a dense, well-connected network for our analyses.

And which types of exercise did it identify as most effective?

We classified treatments according to eleven specific types of exercises (core strengthening, general strengthening, aerobic exercises, stretching, Pilates, yoga, functional restoration, the McKenzie method, flexibility, mixed exercises and ‘other’ specific types).

We found that all exercise types were more effective than minimal treatment and that Pilates, the McKenzie method and functional restoration were more effective than other types of exercise treatment for reducing pain intensity and functional limitations.

A high dose of most exercise treatments appeared to reduce pain and functional limitation outcomes more than a low dose, and the addition of co-interventions appeared to improve the effectiveness of most exercise types for pain and functional limitation outcomes.

But other types of exercise were still also effective?

Yes, we found that all exercise types were better than minimal treatment in reducing pain intensity and improving functioning.

So people with chronic low back pain should be encouraged to perform the exercise that they enjoy and will do consistently.

The most effective forms of exercise won’t achieve their full benefits without compliance.

If a patient has a preference for a specific type of exercise, they should be encouraged to use that exercise.

>> Associate Professor Jill Hayden, the lead author on the Cochrane review of exercise for chronic low back pain, is a faculty member in the Department of Community Health and Epidemiology, Faculty of Medicine, Dalhousie University in Halifax, Canada.