What has happened?
The 2017 Cochrane review of exercise therapy was the subject of a serious complaint which highlighted flaws in its methodology and the methodology of the studies which it reviewed. Cochrane has been working with the review authors to deal with the complaint for over a year. It has now published an update of the review.
What is Cochrane and why is this important news?
Cochrane is an independent agency made up of a network of researchers and organisations from around the world. It produces systematic reviews which evaluate the quality of medical evidence. In their own words they try “to identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a specific research question.” Cochrane is very well-respected (it is often used in medical schools to demonstrate the ‘gold standard’ of evaluating the evidence for therapies), and its reviews are considered highly credible.
The Cochrane review which finds that exercise therapy is a useful intervention in treating ME/CFS has been a major obstacle to getting policy change around the recommendation of GET for ME/CFS. It is also directly problematic for patients as well-meaning doctors seeking to obtain the best up-to-date information will often consult with the Cochrane review to check the latest understanding of a condition or treatment.
Is this good news or bad news for people with ME/CFS?
It is good news that Cochrane recognised the seriousness of the complaint and the issues with GET research. Unfortunately, the updated review doesn’t really address them. The updated review concludes that there is low-moderate certainty about the evidence that GET may alleviate some symptoms of ME/CFS and recommends more research.
The updated review does acknowledge that the evidence only applies to patients diagnosed with the (very broad) Oxford or Fukuda diagnostic criteria and may not apply to people diagnosed with other criteria. Emerge Australia follows the recommendation of the NHMRC ME/CFS Advisory Committee, that ME/CFS research should be based on either the Canadian Consensus Criteria or International Consensus Criteria, which both require post-exertional malaise to be included as a key symptom for diagnosis. Oxford and Fukuda diagnostic criteria rely on fatigue as the primary symptom and therefore may capture people with a very wide range of fatiguing conditions, including depression and mental illness. It is good that Cochrane have acknowledged that the evidence is only applicable for people diagnosed with these broader criteria, but we feel that this distinction will be of little help to patients sitting with their doctor (or applying for DSP or NDIS) and trying to explain that exercise hasn’t helped or has made them feel worse.
The updated review also acknowledges that the “evidence regarding adverse effects is uncertain”. This is an improvement on the previous version of the review, which concluded that “no evidence suggests that exercise therapy may worsen outcomes”, although we believe that this still does not adequately reflect the experience of many patients.
Is there any good news?
Yes! The new Editor-in-Chief of Cochrane, Dr Karla Soares-Weiser, has acknowledged that the updated review doesn’t resolve the issues, and has announced that Cochrane will be undertaking a full update of this review. This is an important step. Dr Soares-Weiser has also said that Cochrane will be engaging with ME/CFS advocacy groups around the world to ensure that the new review includes the patient perspective. We are pleased about this decision and will be writing to Dr Soares-Weiser to ask to be included in this process.