Chang, Chia-Jung, Hung, Li-Yuan, Kogelnik, Andreas M et al. · Healthcare (Basel, Switzerland) · 2021 · DOI
This study examined severely ill ME/CFS patients who are mostly housebound or bedbound—a group that hasn't received much research attention. Researchers found that fatigue, pain, and thinking difficulties were the most common complaints, and patients showed distinct sleep problems and hormone imbalances. The study suggests that ME/CFS and long COVID may share similar mechanisms, meaning treatments discovered for one condition could potentially help the other.
This study addresses a critical research gap by focusing on the most severely affected ME/CFS patients, whose experiences are often underrepresented in clinical research. The identification of consistent biological abnormalities (cortisol dysfunction, sleep architecture changes) and the proposed mechanistic similarities with long COVID could accelerate development of diagnostic tests and treatments. Understanding severe ME/CFS may also inform prevention and management strategies for long COVID.
This study cannot establish causation—for example, cortisol abnormalities may result from severe illness rather than cause the disease. The cross-sectional design cannot determine whether observed symptoms and laboratory findings are primary disease mechanisms or secondary consequences of prolonged immobility and illness. The absence of acute infection markers does not rule out persistent viral reservoirs or post-infectious immune dysregulation.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Chang, Chia-Jung, Hung, Li-Yuan, Kogelnik, Andreas M, Kaufman, David, Aiyar, Raeka S, Chu, Angela M, et al. (2021). A Comprehensive Examination of Severely Ill ME/CFS Patients.. Healthcare (Basel, Switzerland). https://doi.org/10.3390/healthcare9101290
BibTeX
@article{mecfsatlas-chang-2021-comprehensive-examination,
author = {Chang, Chia-Jung and Hung, Li-Yuan and Kogelnik, Andreas M and Kaufman, David and Aiyar, Raeka S and Chu, Angela M and Wilhelmy, Julie and Li, Peng and Tannenbaum, Linda and Xiao, Wenzhong and Davis, Ronald W},
title = {A Comprehensive Examination of Severely Ill ME/CFS Patients.},
journal = {Healthcare (Basel, Switzerland)},
year = {2021},
doi = {10.3390/healthcare9101290},
note = {PubMed: 34682970},
url = {https://www.mecfsatlas.com/evidence/chang-2021-comprehensive-examination},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-26. https://www.mecfsatlas.com/evidence/chang-2021-comprehensive-examination
Contribute
Private, reviewed by a human. Not a public comment thread.