Holtzman, Carly S, Bhatia, Shaun, Cotler, Joseph et al. · Diagnostics (Basel, Switzerland) · 2019 · DOI
This study worked directly with ME/CFS patients to create a better way to measure post-exertional malaise (PEM)—the symptom where activity makes you feel significantly worse. Over 1,500 patients completed a survey to help researchers understand what aspects of PEM are most important to measure, including what triggers it, how quickly symptoms start, and how long they last. The study shows that involving patients in designing assessment tools leads to more thorough and meaningful measurements.
PEM is a core defining feature of ME/CFS, yet no gold-standard measurement tool existed. Better assessment of PEM is essential for research studies, clinical diagnosis, and helping doctors understand disease severity and progression. This patient-centered approach demonstrates that people living with ME/CFS possess critical insights that improve scientific measurement and ultimately clinical care.
This study does not prove that the newly developed PEM instrument is valid or reliable for clinical diagnosis—those properties require additional validation testing. It does not establish causation between specific triggers and PEM severity, nor does it identify the biological mechanisms underlying post-exertional malaise. The study describes what patients report about their symptoms but does not correlate these reports with objective physiological measures.
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
Holtzman, Carly S, Bhatia, Shaun, Cotler, Joseph, & Jason, Leonard A (2019). Assessment of Post-Exertional Malaise (PEM) in Patients with Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS): A Patient-Driven Survey.. Diagnostics (Basel, Switzerland). https://doi.org/10.3390/diagnostics9010026
BibTeX
@article{mecfsatlas-holtzman-2019-assessment-post,
author = {Holtzman, Carly S and Bhatia, Shaun and Cotler, Joseph and Jason, Leonard A},
title = {Assessment of Post-Exertional Malaise (PEM) in Patients with Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS): A Patient-Driven Survey.},
journal = {Diagnostics (Basel, Switzerland)},
year = {2019},
doi = {10.3390/diagnostics9010026},
note = {PubMed: 30832336},
url = {https://www.mecfsatlas.com/evidence/holtzman-2019-assessment-post},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-26. https://www.mecfsatlas.com/evidence/holtzman-2019-assessment-post
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