Trends in the incidence of chronic fatigue syndrome and fibromyalgia in the UK, 2001-2013: a Clinical Practice Research Datalink study.
Collin, Simon M, Bakken, Inger J, Nazareth, Irwin et al. · Journal of the Royal Society of Medicine · 2017 · DOI
Quick Summary
This study looked at how often ME/CFS and fibromyalgia were diagnosed in UK general practices between 2001 and 2013 using medical records. The researchers found that ME/CFS diagnoses decreased over time, while fibromyalgia diagnoses increased. Interestingly, people in poorer areas were less likely to be diagnosed with ME/CFS but more likely to be diagnosed with fibromyalgia compared to people in wealthier areas.
Why It Matters
Understanding temporal trends and socioeconomic patterns in ME/CFS diagnosis is crucial for healthcare planning and identifying potential diagnostic disparities. The finding of lower diagnosis rates in more deprived areas may indicate barriers to diagnosis, care inequality, or differences in healthcare-seeking behavior that warrant further investigation. This study provides baseline epidemiological data essential for tracking progress in disease recognition and ensuring equitable care across socioeconomic groups.
Observed Findings
ME/CFS annual incidence declined from 17.5 to 12.6 per 100,000 people (2001–2013), representing a 2.8% annual decrease.
Fibromyalgia incidence decreased from 32.3 to 27.1 per 100,000 (2001–2007), then increased to 38.2 per 100,000 by 2013.
ME/CFS diagnosis rates were 39% lower in the most deprived socioeconomic quintile compared to the least deprived.
Fibromyalgia diagnosis rates were 40% higher in the most deprived socioeconomic quintile compared to the least deprived.
General fatigue symptoms were recorded at a rate of 2,246 per 100,000 annually, substantially higher than specific diagnostic labels.
Inferred Conclusions
Recorded diagnoses of ME/CFS have declined since 2001, potentially reflecting shifts in diagnostic criteria, clinical recognition, or healthcare practices rather than true disease incidence.
Fibromyalgia diagnoses have increased overall in recent years, suggesting either increased disease occurrence or improved recognition in primary care.
Significant socioeconomic disparities exist in diagnosis rates for both conditions, with opposite patterns that may reflect differential access to diagnosis, healthcare utilization, or recognition of these syndromes in deprived versus affluent populations.
Remaining Questions
Does the decline in recorded ME/CFS diagnoses reflect true reduction in disease incidence, or does it indicate missed diagnoses and underascertainment in primary care?
What This Study Does Not Prove
This study does not prove that the actual incidence of ME/CFS has declined—only that recorded diagnoses have decreased, which could reflect changing diagnostic practices, physician awareness, or case definitions rather than true disease incidence. The observed socioeconomic disparities do not establish whether deprivation causes lower diagnosis rates or whether other unmeasured factors (such as differences in symptom presentation, health literacy, or access to specialists) explain the pattern. This is observational data and cannot establish causation for any of the associations reported.
Tags
Symptom:Fatigue
Method Flag:PEM Not DefinedWeak Case DefinitionMixed Cohort
What specific barriers in deprived areas lead to lower ME/CFS diagnosis rates but higher fibromyalgia diagnosis rates—are these related to clinical presentation, healthcare access, provider training, or patient factors?
How has diagnostic practice and clinical awareness evolved since 2013, and have recent efforts to improve ME/CFS recognition changed these epidemiological trends?
What proportion of patients with ME/CFS symptoms in the community remain undiagnosed or misdiagnosed as other conditions?