Prevalence and measurement of post-exertional malaise in post-acute COVID-19 syndrome: A systematic review and meta-analysis.
An, Yi, Guo, Ziyu, Fan, Jin et al. · General hospital psychiatry · 2024 · DOI
Quick Summary
Researchers looked at 12 studies involving 2,665 patients with long COVID to understand how common post-exertional malaise (PEM)—a worsening of symptoms after physical or mental effort—is among those affected. They found that more than half of long COVID patients experience PEM. The study also identified seven different questionnaires that researchers use to measure PEM, with the DePaul Symptom Questionnaire being the most commonly used tool.
Why It Matters
PEM is recognized as a core symptom in long COVID and shares mechanistic similarities with ME/CFS. Establishing PEM prevalence (>50%) in PACS validates its significance as a treatment target and highlights the urgent need for evidence-based interventions. Standardizing PEM measurement tools is essential for clinical trials and comparative research across ME/CFS and long COVID populations.
Observed Findings
Over half of post-acute COVID-19 syndrome patients (55%) experience post-exertional malaise at 3 months or longer after infection
Seven different questionnaires have been used to measure PEM in long COVID research
The DePaul Symptom Questionnaire-Post Exertional Malaise (DSQ-PEM) is the most frequently utilized measurement tool
PEM was identified as part of the official core outcome set for post-acute COVID-19 syndrome
Inferred Conclusions
Post-exertional malaise is a highly prevalent and debilitating symptom affecting the majority of PACS patients, warranting urgent development of effective treatment strategies
Standardization of PEM measurement instruments is necessary to improve research quality and enable meaningful comparisons across studies
The high disease burden of PEM in PACS justifies increased research and clinical attention to this symptom
Remaining Questions
What are the underlying biological and physiological mechanisms that cause PEM in long COVID, and how do they compare to those in ME/CFS?
Which PEM measurement tool best predicts functional outcomes and treatment response in long COVID patients?
What This Study Does Not Prove
This review does not establish the biological mechanisms underlying PEM or determine whether PEM in PACS and ME/CFS are identical conditions. It cannot prove causation or establish whether PEM is directly caused by COVID-19 viral effects versus other post-infectious processes. The prevalence estimate depends on how well studies defined and measured PEM, which varied across included studies.