Meta-analysis investigating post-exertional malaise between patients and controls by Abigail Brown and Leonard Jason in J Health Psychol. 2018 Jul [First published 5 July 2018]
Post-exertional malaise is either required or included in many previously proposed case definitions of myalgic encephalomyelitis/chronic fatigue syndrome. A meta-analysis of odds ratios (ORs; association between patient status and post-exertional malaise status) and a number of potential moderators (i.e. study-level characteristics) of effect size were conducted.
Post-exertional malaise was found to be 10.4 times more likely to be associated with a myalgic encephalomyelitis/chronic fatigue syndrome diagnosis than with control status. Significant moderators of effect size included patient recruitment strategy and control selection.
These findings suggest that post-exertional malaise should be considered a cardinal symptom of myalgic encephalomyelitis/chronic fatigue syndrome.
[The article lists possible definitions of PEM, including:
- post-exertional neuroimmune exhaustion (Carruthers et al., 2011);
- “an inappropriate loss of physical and mental stamina, rapid muscular and cognitive fatigability … and a tendency for other associated symptoms to worsen” (Carruthers et al., 2003);
- “prolonged exacerbation of a patient’s baseline symptoms after physical/cognitive/orthostatic stress; [it] may be delayed relative to the trigger.” (IOM, 2015)]