Chronic Widespread Pain in a tertiary pain clinic: classification overlap and use of a patient generated quality of life instrument.
Tschudi-Madsen, Hedda, Rødevand, Linn N, Bøymo Kaarbø, Mette et al. · Scandinavian journal of pain · 2019 · DOI
Quick Summary
This study looked at 33 patients with widespread pain to understand how different diagnostic labels (fibromyalgia, chronic fatigue syndrome, and bodily distress syndrome) overlap and apply to the same people. Researchers also tested whether a patient-created quality-of-life survey could capture things that standard questionnaires miss. They found that most patients had very low quality of life scores, and that the newer diagnostic criteria for fibromyalgia work better together than older versions.
Why It Matters
This study clarifies the substantial diagnostic overlap between fibromyalgia, ME/CFS, and related conditions, supporting more unified terminology under ICD-11. The finding that patient-generated quality-of-life measures capture unique clinical information not detected by standard questionnaires has direct relevance for comprehensive assessment and treatment planning in ME/CFS and related complex symptom disorders.
Observed Findings
All 33 patients (100%) met criteria for musculoskeletal-type single-organ Bodily Distress Syndrome.
81.8% of patients met the 2016 modified American College of Rheumatology fibromyalgia criteria.
30.3% met Canada criteria for Chronic Fatigue Syndrome.
Patients had very low quality of life, with mean Patient Generated Index score of 28.9 out of 100 (SD 19.8).
Modern fibromyalgia criteria sets (2010, 2011, 2016) showed strong agreement with each other (κ=0.673–0.766) but poor agreement with the 1990 criteria (κ=0.279).
Inferred Conclusions
Widespread pain patients should be described using the term "musculoskeletal-type single-organ BDS" under ICD-11 classification.
The 2016 revision of fibromyalgia criteria better reflects current understanding and should be preferred over earlier criteria in new studies.
Patient-generated quality-of-life measures provide clinically useful information beyond standard patient-reported outcome measures in complex symptom disorders.
Historical studies using 1990 fibromyalgia criteria are not directly comparable to those using later criteria sets.
Remaining Questions
Do the diagnostic overlaps observed in this tertiary clinic population reflect the prevalence of overlap in primary care or general populations?
What This Study Does Not Prove
This study does not establish causation or temporal relationships between conditions, only their co-occurrence in a specialized clinic population. The small sample size (n=33) and lack of control group limits generalizability beyond tertiary pain clinic settings. The cross-sectional design cannot determine whether diagnostic overlap reflects shared underlying mechanisms or simply similar symptom presentations.
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 →
Contribute
Private, reviewed by a human. Not a public comment thread.