Leonard Jason, Julia Newton en anderen hebben op basis van de DePaul vragenlijst en op basis

van eigen criteria patienten ingedeeld in vier (zelf gedefinieerde) categorieen (zie afbeelding onder):

1. onverklaarde chronische vermoeidheid,
2. chronische vermoeidheid die verklaard wordt door een medische of psychische aandoening,
3. Neuroendocrineimmune Dysfunction Syndrome (NDS) = "CVS" volgens de definitie van Jason, en
4. "ME", volgens de definitie van Jason, die wel strenger is, maar niet lijkt op ME/Ramsay.

Case definitions integrating empiric and consensus perspectives.

Fatigue: Biomedicine, Health & Behavior. 2016 Jan 19. doi: 10.1080/21641846.2015.1124520.

Jason LA, McManimen S, Sunnquist M, Brown A, Furst J, Newton JL, Strand EB.

Abstract

Background:

There has been considerable controversy regarding how to name and define

the illnesses known as myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS).

The Institute of Medicine (IOM) report has proposed

new clinical criteria and a new name for this illness,

but aspects of these recommendations have been scrutinized by patients and scientists.

Purpose:

It is possible that both empiric and consensus approaches could be used

to help settle some of these diagnostic challenges.

Using patient samples collected in the USA, Great Britain, and Norway (N=556),

the current study attempted to categorize patients

using more general as well as more restricted case definitions.

Results:

Overall, the outcomes suggest that there might be four groupings of patients,

with the broadest category involving those with chronic fatigue (N=62),

defined by six or more months of fatigue

which cannot be explained by medical or psychiatric conditions.

A second category involves those patients

who have chronic fatigue that can be explained by a medical or psychiatric condition (N=47).

A third category involves more specific criteria

that have been posited both by

the IOM report, Canadian Clinical Case criteria, ME-ICC criteria and a more empiric approach.

These efforts have specified domains of substantial reductions of

activity, post-exertional malaise, neurocognitive impairment, and sleep dysfunction

(N=346).

Patients with these characteristics were more functionally impaired

than those meeting just chronic fatigue criteria, p < .05.

Finally, those meeting even more restrictive ME criteria proposed by Ramsay,

identified a smaller and even more impaired group, p < .05.

Conclusion:

It is important that scientists world-wide develop consensus on

how to identify and classify patients using clinical and research criteria, and

ultimately develop subtypes within such categories.

Keywords:

Myalgic encephalomyelitis; chronic fatigue syndrome; case definition

http://www.tandfonline.com/doi/full/10.1080/21641846.2015.1124520