Friedberg, Fred, Sohl, Stephanie J · Journal of behavioral medicine · 2009 · DOI
This study followed 75 people with ME/CFS for 2 years and compared different ways of measuring how they were doing. Researchers used both traditional questionnaires and home-based measurements like activity trackers and daily fatigue diaries. They found that people who reported feeling better had lower fatigue levels and stood up more often at home, but these improvements didn't always show up on activity trackers or psychological tests.
This research highlights that standard questionnaires may not capture all meaningful improvements in ME/CFS, and that home-based measurements like activity diaries can reveal real changes in daily functioning that patients notice. Understanding which outcome measures best reflect actual symptom change is essential for designing better treatment studies and recognizing patient progress.
This study does not prove that improved activity levels *cause* fatigue reduction, only that they are associated. The findings are limited to a relatively high-functioning subset of ME/CFS patients and may not apply to more severely affected individuals. Correlation between actigraphy and self-reported function does not establish whether activity changes are therapeutic or represent post-activity crashes.
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
Friedberg, Fred & Sohl, Stephanie J (2009). Longitudinal change in chronic fatigue syndrome: what home-based assessments reveal.. Journal of behavioral medicine. https://doi.org/10.1007/s10865-008-9189-9
BibTeX
@article{mecfsatlas-friedberg-2009-longitudinal-change,
author = {Friedberg, Fred and Sohl, Stephanie J},
title = {Longitudinal change in chronic fatigue syndrome: what home-based assessments reveal.},
journal = {Journal of behavioral medicine},
year = {2009},
doi = {10.1007/s10865-008-9189-9},
note = {PubMed: 19101789},
url = {https://www.mecfsatlas.com/evidence/friedberg-2009-longitudinal-change},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-28. https://www.mecfsatlas.com/evidence/friedberg-2009-longitudinal-change
Contribute
Private, reviewed by a human. Not a public comment thread.