Burton, Christopher, Knoop, Hans, Popovic, Nikola et al. · BioPsychoSocial medicine · 2009 · DOI
This study measured how people with ME/CFS move and rest over a 12-day period compared to healthy people. Researchers found that people with ME/CFS have activity patterns that are more repetitive and predictable—like a broken record—whereas healthy people's activity patterns are more varied and flexible. This difference held true even when accounting for the fact that ME/CFS patients were less active overall.
This study provides an objective, quantifiable measure of ME/CFS pathology beyond simple reduced activity counts—showing that the *pattern* of activity itself is fundamentally altered. If validated, complexity measures could become a useful objective biomarker for diagnosis and disease monitoring, addressing a major unmet need in ME/CFS clinical practice.
This study does not establish whether reduced complexity causes symptom worsening or is merely a consequence of the disease. It also does not prove complexity measures can reliably diagnose ME/CFS in clinical practice, nor does it explain the biological mechanisms underlying reduced complexity. Causality cannot be inferred from this cross-sectional observation.
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
Burton, Christopher, Knoop, Hans, Popovic, Nikola, Sharpe, Michael, & Bleijenberg, Gijs (2009). Reduced complexity of activity patterns in patients with chronic fatigue syndrome: a case control study.. BioPsychoSocial medicine. https://doi.org/10.1186/1751-0759-3-7
BibTeX
@article{mecfsatlas-burton-2009-reduced-complexity,
author = {Burton, Christopher and Knoop, Hans and Popovic, Nikola and Sharpe, Michael and Bleijenberg, Gijs},
title = {Reduced complexity of activity patterns in patients with chronic fatigue syndrome: a case control study.},
journal = {BioPsychoSocial medicine},
year = {2009},
doi = {10.1186/1751-0759-3-7},
note = {PubMed: 19490619},
url = {https://www.mecfsatlas.com/evidence/burton-2009-reduced-complexity},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-29. https://www.mecfsatlas.com/evidence/burton-2009-reduced-complexity
Contribute
Private, reviewed by a human. Not a public comment thread.