Schafer, Charles, Evans, Meredyth, Jason, Leonard A et al. · Journal of prevention & intervention in the community · 2015 · DOI
ME/CFS diagnosis requires showing a significant drop in daily activities, but doctors have struggled to measure this fairly. This study looked at different ways to measure activity levels—including work, quality of life surveys, and activity trackers—to find which method works best. The researchers found that tracking current work activities was the most useful way to show the substantial reduction in functioning that ME/CFS patients experience.
Establishing a clear, measurable definition of 'substantial activity reduction' is essential for consistent ME/CFS diagnosis and for tracking disease severity in research. This work helps standardize how clinicians and researchers quantify disability, which improves diagnostic accuracy and enables better comparison across studies. For patients, clearer diagnostic criteria mean better recognition of their condition and more appropriate medical evaluation.
This study does not establish causation—finding that work activity is associated with health measures does not mean that working more would improve health or that activity reduction causes better outcomes. The cross-sectional design captures only a single time point and cannot determine whether activity levels predict future health trajectories. The findings may not generalize to all ME/CFS populations or apply equally across different disease severity levels.
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
Schafer, Charles, Evans, Meredyth, Jason, Leonard A, So, Suzanna, & Brown, Abigail (2015). Measuring substantial reductions in activity.. Journal of prevention & intervention in the community. https://doi.org/10.1080/10852352.2014.973242
BibTeX
@article{mecfsatlas-schafer-2015-measuring-substantial,
author = {Schafer, Charles and Evans, Meredyth and Jason, Leonard A and So, Suzanna and Brown, Abigail},
title = {Measuring substantial reductions in activity.},
journal = {Journal of prevention & intervention in the community},
year = {2015},
doi = {10.1080/10852352.2014.973242},
note = {PubMed: 25584524},
url = {https://www.mecfsatlas.com/evidence/schafer-2015-measuring-substantial},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-27. https://www.mecfsatlas.com/evidence/schafer-2015-measuring-substantial
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