By David Tuller, DrPH
The other day, I posted yet another blog about Cochrane’s deeply flawed 2019 review of exercise therapy for what it called chronic fatigue syndrome (CFS), and the organization’s decision last December to abandon a planned update. Specifically, I was commenting on a response from the review’s lead author, Lillebeth Larun, to a comment from the Independent Advisory Group, which Cochrane had designated to help oversee the development of the new version of the review.
It seemed to me that the response from Larun, a researcher and associate professor at the Norwegian Institute for Public Health, presented a solid case for the need for an update–although that was clearly not her intention. I decided to make this point to Cochrane’s chief executive officer, Karla Soares-Weiser–not that I expect to receive a positive response, or any response at all. I included Toby Lasserson, Cochrane’s acting editor in chief, on the e-mail.
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Dear Dr. Soares-Weiser:
In June, Lillebeth Larun, the lead author of Cochrane’s much-disputed review of exercise therapy for chronic fatigue syndrome, responded to concerns raised in a comment from consumer health advocate Hilda Bastian. Bastian had written on behalf of the Independent Advisory Group created by Cochrane to help oversee development of a new review of exercise therapy for myalgic encephalomyelitis/chronic fatigue syndrome. (ME/CFS is currently the most common name for the clinical entity in question.) As you know, Cochrane announced last December that it was abandoning that project.
As Bastian noted in her comment, the review’s presentation of exercise therapy as a normative approach is inaccurate. As an example, she cited an assertion from the review’s “plain language summary” that “exercise therapy is recommended by treatment guidelines.” This statement was arguably true in 2019, when the text was written. However, the claim is now obsolete and hard to defend, given that the 2021 guidance on ME/CFS from the National Institute for Health and Care Excellence rescinded the organization’s prior endorsement of exercise therapy.
Ironically, some of Larun’s comments reflect what the patient and advocacy community have argued for years–that the studies included in the review used definitions for the illness that conflated “chronic fatigue syndrome” with the symptom of “chronic fatigue.” Larun now acknowledges that the review is not solely about patients with CFS, despite its categorical title, but also about the larger category of those suffering from “idiopathic chronic fatigue.”
She further concedes that the review’s findings “may not apply” to people diagnosed by “narrower” definitions. These “narrower” and more recent definitions all require the presence of post-exertional malaise (PEM)–now considered the hallmark feature of ME/CFS.
Efforts to defend the 2019 review as still relevant are seriously misguided. It is no slight to Larun and her co-authors to point out that the protocol for the review is deficient for many reasons—not least because it was written in 2002. Since then, scientific understanding of ME/CFS, including the central role of PEM, has advanced.
Given Larun’s responses, the need for a new review of exercise therapy for ME/CFS should be self-evident. Cochrane’s reversal on that score remains hard to square with its declared commitment to providing reliable and actionable information.
Best–David
David Tuller, DrPH
Senior Fellow in Public Health and Journalism
Center for Global Public Health
School of Public Health
University of California, Berkeley