E3 PreliminaryPreliminaryPEM not requiredRegistry-ResourcePeer-reviewedReviewed
A pilot registry of unexplained fatiguing illnesses and chronic fatigue syndrome.
Brimmer, Dana J, Maloney, Elizabeth, Devlin, Rebecca et al. · BMC research notes · 2013 · DOI
Quick Summary
This study tested whether doctors and patient groups could help identify people with ME/CFS for a patient registry (a database of medical information). Researchers in Georgia contacted healthcare providers and a local ME/CFS support group to refer patients for evaluation. Of 104 people who completed clinic visits, 36% had ME/CFS, 17% had fatigue that didn't quite meet ME/CFS criteria, and 47% had other medical or psychiatric conditions instead. This shows that many people with fatigue symptoms may have treatable conditions other than ME/CFS.
Why It Matters
This study demonstrates the practical feasibility of building a ME/CFS registry and shows that nearly half of patients initially suspected of having ME/CFS actually have other treatable conditions. Understanding the difference between ME/CFS and other fatiguing illnesses is crucial for patients to receive appropriate diagnosis and treatment.
Observed Findings
- Of 104 participants completing evaluation, 36% (n=37) met CFS criteria, 17% (n=18) had insufficient fatigue, and 47% (n=49) had exclusionary medical or psychiatric conditions.
- Healthcare providers (42 of 827 registered) referred 88 patients with 66% completion rate; support group members (53 of 188) had 87% completion rate.
- Classification varied significantly by referral type: providers referred more CFS cases while support groups identified more exclusionary conditions.
- Family practice and internal medicine specialists made the most referrals and identified the highest number of CFS cases.
Inferred Conclusions
- Registries without clinical examination may overestimate or misclassify ME/CFS due to enrollment bias depending on referral source.
- Education outreach partnerships with local organizations are effective in engaging both healthcare providers and patient communities for registry enrollment.
- The high proportion of exclusionary medical and psychiatric conditions identified underscores the need for comprehensive medical management in patients with fatiguing illnesses.
Remaining Questions
- Why do different referral sources (providers vs. support groups) identify different proportions of exclusionary conditions?
- What specific medical and psychiatric conditions were most commonly identified as exclusionary diagnoses?
What This Study Does Not Prove
This pilot study does not prove the prevalence of ME/CFS in the general population, as it was limited to one geographic area and relied on voluntary referral and self-selection. It does not establish definitive diagnostic criteria for ME/CFS beyond the 1994 case definition used, nor does it address why referral source affects diagnostic classification patterns.
Tags
Symptom:Fatigue
Method Flag:Weak Case DefinitionNo ControlsSmall SampleExploratory OnlyMixed CohortPEM Not Defined
Metadata
- DOI
- 10.1186/1756-0500-6-309
- PMID
- 23915640
- Review status
- Editor reviewed
- Evidence level
- Early hypothesis, preprint, editorial, or weak support
- Last updated
- 12 April 2026
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 →
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