Two groups of American researchers debate the appropriateness of using case definitions for research purposes.
Article abstract:
Mistaken conclusions about systemic exercise intolerance disease being comparable to research case definitions of CFS: a rebuttal to Chu et al., by Leonard A. Jason, Madison Sunnquist, Kristen Gleason, Pamela Fox in Fatigue: Biomedicine, Health & Behavior
August 7, 2017 [Preprint]
The recent article by Chu et al. contrasted different case definitions that have been used to describe chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME). In particular, their study compared the new Institute of Medicine (IOM) criteria for systemic exertion intolerance disease (SEID) with three other ME and CFS case definitions.
We appreciate these investigators attempting to use and operationalize the new IOM criteria; however, we disagree with their main conclusion that the percentage of patients selected by the IOM criteria is comparable to the percentage selected by other research case definitions. This conclusion could potentially encourage investigators to use the IOM criteria for research purposes.
In this commentary, we discuss our observations of the Chu et al. article with respect to their methodology, illustrating how the conclusions of an investigation can be influenced by the manner in which case definitions are operationalized.
Article abstract:
Differences of opinion on systemic exercise intolerance disease are not ‘mistakes’: a rejoinder to Jason, Sunnquist, Gleason and Fox, by Lily Chu, Ian J. Valencia, Jose G. Montoya in Fatigue: Biomedicine, Health & Behavior, 10 Aug 2017
Differences of opinion about how case definitions are operationalized should not be characterized as ‘mistaken.’ Despite limitations, our study provides insight into how systemic exertion intolerance disease (SEID) criteria perform early in the course of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) compared to other
case definitions.
To facilitate early, accurate diagnosis, research needs to be performed, ideally, prospectively with subjects who have not been ill for years. In addition, results of past treatment studies may not be applicable to many ME/CFS patients because criteria used for research differed from patients’ clinical presentations. To avoid this potential mismatch between research employing the new clinically-focused SEID criteria should be promoted, rather than discouraged.
