ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

61–80 of 510 studies

E2 ModerateBehavioralPEM not requiredCross-Sectional

Who receives a diagnostic label for fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome? A study in the lifelines cohort.

Tattan, Mais, Hanssen, Denise J C, Rosmalen, Judith G M·Journal of psychosomatic research·2026

This study looked at over 150,000 people to understand why some people with ME/CFS, fibromyalgia, or irritable bowel syndrome receive a diagnosis while others with the same symptoms do not. The researchers found that only a small number of people who meet the criteria for these conditions actually get diagnosed—about 14% for ME/CFS. Several factors like sex, education level, other health conditions, and how often people visit doctors affected whether they received a diagnosis.

Diagnostics

E2 ModerateCohortPEM unclearCross-Sectional

3D Virtual Reality Performance Metrics as a Future Fatigue Biomarker in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Ladek, Anja-Maria, Priebe, Leonie, Harrer, Thomas et al.·Biomedicines·2026

Researchers tested how quickly 60 ME/CFS patients and 60 healthy controls could react to visual tasks presented in 3D virtual reality. ME/CFS patients showed slower reaction times across all difficulty levels, and they improved less with practice than controls did. The study reports an association between ME/CFS and prolonged reaction times, though the findings are preliminary and whether this could become a reliable test for fatigue severity requires further validation.

BiomarkersDiagnosticsCognitive Impairment

E2 ModerateCohortPEM unclearCase-Control

Sleep in myalgic encephalomyelitis/chronic fatigue syndrome shows marked night-to-night fluctuation under free-living conditions-results from a matched case-control study.

Saurel, Maïtena, Fornasieri, Isabelle, Del Sordo, Giovanna C et al.·Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine·2026

This study observed that people with ME/CFS who wore sleep-tracking wristbands for a week showed poorer sleep quality and more night-to-night variability in how well they slept compared to matched controls—even though they spent more time in bed. The sleep pattern was unstable from night to night, which may be an important feature of ME/CFS sleep problems that laboratory studies (typically 1–2 nights) do not capture.

SleepDiagnostics

E2 ModeratePEM unclearRegistry-Resource

Risk factors for severe post-COVID condition in children, adolescents, and young adults.

Donath, Quirin, Haegele, Matthias, Schindler, Daniela et al.·European journal of pediatrics·2026

This observational study from a German pediatric hospital followed 120 children and young adults with post-COVID condition (PCC), observing that those with more severe illness were more likely to have had 12 or more symptoms during their initial COVID-19 infection, alongside other acute symptoms such as trouble concentrating and fainting-like episodes. One quarter of participants met criteria for ME/CFS, and all of these were in the severely affected group; by analogy, if similar patterns apply to ME/CFS patients, early identification of high-symptom-burden acute illness might help predict who develops severe long-term illness. These findings are preliminary and come from a single hospital site.

Severe MEAutonomic Nervous SystemDiagnosticsCognitive Impairment

E2 ModerateCohortPEM unclearCase-Control

Interpreting hand grip strength in hospital employees with post-COVID syndrome compared to non-infected controls: a case-control study.

Tack, Matthias, Gruber, Rosalie, Betting, Leia et al.·Scientific reports·2026

This small study compared hand grip strength in 19 hospital workers with post-COVID syndrome (including 7 who met ME/CFS criteria) to 23 healthy controls. Researchers found that grip strength tended to be lower in the post-COVID group, particularly when tested a second time after a 60-minute break, which might suggest difficulty recovering after repeated effort. However, these are preliminary findings from a small group, and the authors note that grip strength alone is not reliable enough to diagnose post-COVID syndrome.

DiagnosticsPost-Exertional Malaise

E2 ModerateCohortPEM unclearObservational

Prediction of post-COVID chronic fatigue syndrome using data mining and machine learning techniques in Isfahan COVID cohort study.

Nematbakhsh, Shayan, Mohammadifard, Noushin, Riahi, Roya et al.·Journal of infection and public health·2026

Researchers used machine learning to identify factors associated with post-COVID fatigue in a cohort of 3,850 patients in Isfahan, Iran. The analysis identified 37 factors linked to fatigue; anxiety, BMI, depression, irritability, and memory issues were among the strongest predictors. A machine learning model achieved 85% accuracy at identifying patients at risk, though these results are based on observed associations and have not yet been validated in independent populations.

Diagnostics

E2 ModerateCohortPEM unclearObservational

Cardiopulmonary exercise test results do not change over two sequential days in patients with chronic fatigue syndrome.

Mancini, Donna M, Cook, Dane B, Brunjes, Danielle L et al.·Frontiers in physiology·2026

Researchers asked whether doing two exercise tests on consecutive days could reliably detect post-exertional malaise (PEM) in ME/CFS patients. They found that oxygen consumption and other key exercise measures did not change between Day 1 and Day 2 in either ME/CFS patients or healthy controls. However, ME/CFS patients reported much greater fatigue during exercise and had lower maximum heart rates. One study's findings do not establish whether this two-day test method is truly useful for measuring PEM in clinical practice.

DiagnosticsPost-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome diagnostic reporting in the 2021-2023 National Health Interview Survey.

Fleig, Katherine, Nahin, Richard, Stussman, Barbara et al.·BMC public health·2026

A survey of over 86,000 US adults found that approximately 1.5% reported ever receiving an ME/CFS diagnosis. Among those, about 21% reported they no longer have the condition (Past ME/CFS), though roughly 40–50% of this group still experience symptoms and functional limitations similar to those currently diagnosed. This study observed that people who report having recovered from ME/CFS remain more impaired than those who never had the diagnosis, suggesting that reported recovery does not necessarily mean full symptom resolution.

Diagnostics

E2 ModerateDiagnosticPEM unclearCross-Sectional

Improving myalgic encephalomyelitis population sampling: Applying an online respondent-driven method to address biases in G93.3 register data.

Kielland, Anne, Liu, Jing, Tyldum, Guri et al.·Journal of health psychology·2026

This study looked at how well official medical records capture ME/CFS cases and who gets diagnosed. Researchers found that medical register data misses many cases and disproportionately underrepresents people from lower-income backgrounds. They used a new online method to find ME/CFS patients more accurately and checked whether official diagnoses matched recognized diagnostic criteria.

Diagnostics

E2 ModerateCohortPEM unclearCross-Sectional

Cardiopulmonary Exercise Testing Reveals Functional Limitations and Work Disability in Severe Post-COVID-19 and ME/CFS Patients.

Tomaskovic, Aleksandar, Weber, Vincent, Ochmann, David T et al.·Sports medicine - open·2026

A cross-sectional study of 92 severely ill post-COVID patients found that those meeting ME/CFS criteria had lower measured aerobic capacity (oxygen uptake and power output) on exercise testing compared to post-COVID patients without ME/CFS. Two-thirds of all patients showed objective signs of work disability on testing, and these measurements correlated with patients' own reports of disability and their employment status. The relevance of these findings specifically to ME/CFS requires caution, as the study enrolled primarily post-COVID patients, and the overlap between these conditions remains incompletely understood.

Severe MEDiagnosticsLong COVID OverlapPost-Exertional Malaise

E2 ModeratePEM unclearBiobank-Resource

Defining a High-Quality Myalgic Encephalomyelitis/Chronic Fatigue Syndrome cohort in UK Biobank.

Samms, Gemma L, Ponting, Chris P·NIHR open research·2025

This study looked at how ME/CFS is identified in UK Biobank, a large database of health information from hundreds of thousands of people. Researchers found that about 1 in 100 UK Biobank participants had some evidence of ME/CFS, but only about one-third had strong, consistent evidence across multiple records. When they accounted for people too ill to participate in the study, they estimated that around 410,000 people in the UK have ME/CFS.

Diagnostics

E2 ModerateCohortPEM not requiredCross-Sectional

The Diagnostic Journey of Dysautonomia Patients: Insights from a Patient-Reported Outcome Study.

O'Dell, John A, Walker, Ash, Latham, Andrew J et al.·Journal of patient experience·2025

This study followed 672 adults with dysautonomia (a condition where the nervous system that controls automatic body functions doesn't work properly) to understand how long it takes to get diagnosed and which doctors help with diagnosis. On average, it took 7.7 years for people to receive a diagnosis, and they often saw multiple types of doctors before getting answers. The study found that dysautonomia commonly occurs alongside other conditions like Ehlers-Danlos syndrome, mast cell disorders, and ME/CFS, which can make diagnosis even more confusing.

Autonomic Nervous SystemDiagnostics

E2 ModerateCohortPEM unclearRegistry-Resource

Unequal access to diagnosis of myalgic encephalomyelitis in England.

Samms, Gemma Louise, Ponting, Chris P·BMC public health·2025

This study examined NHS records from England to understand how many people have ME/CFS and whether diagnosis is fair across different groups. Researchers found that about 100,000 people in England have been officially diagnosed with ME/CFS, but the actual number may be much higher—around 404,000 in the UK. The diagnosis rates varied significantly depending on gender, age, ethnicity, and where people live, suggesting some patients are being missed.

Diagnostics

E2 ModerateCohortPEM unclearObservational

Chronicity rhetoric in health and welfare systems inhibits patient recovery: a qualitative, ethnographic study of fibromyalgia care.

Cupit, Caroline, Finlay, Teresa, Pope, Catherine et al.·Social science & medicine (1982)·2025

This study looked at how healthcare and welfare systems talk about fibromyalgia and similar long-term conditions like ME/CFS. Researchers found that when doctors and officials constantly describe these conditions as permanent and unchangeable ('chronicity rhetoric'), it can actually get in the way of patients healing and recovering. The study suggests that changing how we talk about these conditions—and how our support systems are designed—might help patients feel more hopeful and do better.

Diagnostics

E2 ModerateCohortPEM unclearCross-Sectional

Quantifying the Degree of Fatigue in People Reporting Symptoms of Post-COVID-19 Syndrome: Results from a Rasch Analysis.

Mayo, Nancy, Brouillette, Marie-Josée, Fellows, Lesley K et al.·Physiotherapy Canada. Physiotherapie Canada·2025

Researchers in this study developed and tested a new questionnaire to measure fatigue severity in people with post-COVID-19 syndrome. The measure, called the PCS Fatigue Severity Measure V1, performed well in their analysis of 414 participants—it correlated strongly with other fatigue measures and distinguished between people still working and those on sick leave. However, this is early-stage research in a single Canadian cohort, and the authors note that further testing in other populations is needed to confirm the measure's reliability over time.

DiagnosticsPost-Exertional Malaise

E2 ModerateCohortPEM unclearObservational

Assessing the influence of lived-experience experts on healthcare providers in a virtual community of practice: a qualitative study.

Weaver, Stephanie Sargent, Carry, Monique, Bertolli, Jeanne et al.·Frontiers in health services·2025

This study looked at whether having patients with lived experience of Long COVID and ME/CFS help teach doctors made a real difference in patient care. Researchers tracked what these patient-experts recommended to doctors through online training sessions from 2022-2024, and then asked actual patients if their doctors seemed to apply that advice. The main recommendations focused on validating patients' experiences, showing empathy, helping with referrals, and supporting self-care. Patients reported noticing positive changes in how their doctors treated them, suggesting that including patient-experts in medical education actually works.

Diagnostics

E2 ModerateBehavioralPEM not requiredCross-Sectional

Factors associated with having previously received a diagnosis of fibromyalgia, chronic fatigue syndrome and irritable bowel syndrome: A cross sectional DanFunD study.

Tattan, Mais, Ørnbøl, Eva, Wellnitz, Kaare Bro et al.·Journal of psychosomatic research·2024

This study looked at 1,704 people with symptoms of functional somatic disorders (including ME/CFS, fibromyalgia, and irritable bowel syndrome) to understand who had received a diagnosis from a doctor. The researchers found that people—especially women—who had poor quality of life and negative beliefs about their illness were more likely to have received an official diagnosis. The study suggests that factors beyond just having symptoms affect whether people get diagnosed with these conditions.

Diagnostics

E2 ModerateCohortPEM unclearCross-Sectional

[Systems thinking, subjective findings and diagnostic "pigeonholing" in ME/CFS: A mainly qualitative public health study from a patient perspective].

Habermann-Horstmeier, Lotte, Horstmeier, Lukas Maximilian·Deutsche medizinische Wochenschrift (1946)·2024

This German study asked 544 ME/CFS patients about their experiences getting diagnosed and working with doctors. Patients reported that many doctors don't recognize ME/CFS as a real disease, instead dismissing it as purely psychological. The study found that poor diagnosis experiences and lack of doctor recognition of ME/CFS as a biological multisystem illness significantly damage the relationship between patients and their healthcare providers.

Diagnostics

E2 ModerateCohortPEM requiredLongitudinal

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After SARS-CoV-2 Infection.

Unger, Elizabeth R, Lin, Jin-Mann S, Wisk, Lauren E et al.·JAMA network open·2024

This study followed over 4,300 people for up to 12 months to see whether COVID-19 infection caused ME/CFS-like symptoms. Researchers found that about 3-4% of people reported ME/CFS-like symptoms after their acute illness, but this rate was similar whether they had tested positive or negative for COVID-19. The results suggest that while some people do develop long-lasting symptoms after illness, COVID-19 may not be uniquely causing ME/CFS more often than other infections.

DiagnosticsLong COVID Overlap

E2 ModerateCohortPEM not requiredCross-Sectional

Validity and diagnostic overlap of functional somatic syndrome diagnoses.

van der Meulen, Monica L, Bos, Martje, Bakker, Stephan J L et al.·Journal of psychosomatic research·2024

This study looked at how often three common conditions—ME/CFS, fibromyalgia, and irritable bowel syndrome—occur together in the general population. Researchers surveyed nearly 90,000 people and found that these conditions overlap far more often than would happen by pure chance, especially when they last longer and cause more serious symptoms. This suggests these conditions may share common underlying features.

Diagnostics

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Evidence browser

Who receives a diagnostic label for fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome? A study in the lifelines cohort.

3D Virtual Reality Performance Metrics as a Future Fatigue Biomarker in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Sleep in myalgic encephalomyelitis/chronic fatigue syndrome shows marked night-to-night fluctuation under free-living conditions-results from a matched case-control study.

Risk factors for severe post-COVID condition in children, adolescents, and young adults.

Interpreting hand grip strength in hospital employees with post-COVID syndrome compared to non-infected controls: a case-control study.

Prediction of post-COVID chronic fatigue syndrome using data mining and machine learning techniques in Isfahan COVID cohort study.

Cardiopulmonary exercise test results do not change over two sequential days in patients with chronic fatigue syndrome.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome diagnostic reporting in the 2021-2023 National Health Interview Survey.

Improving myalgic encephalomyelitis population sampling: Applying an online respondent-driven method to address biases in G93.3 register data.

Cardiopulmonary Exercise Testing Reveals Functional Limitations and Work Disability in Severe Post-COVID-19 and ME/CFS Patients.

Defining a High-Quality Myalgic Encephalomyelitis/Chronic Fatigue Syndrome cohort in UK Biobank.

The Diagnostic Journey of Dysautonomia Patients: Insights from a Patient-Reported Outcome Study.

Unequal access to diagnosis of myalgic encephalomyelitis in England.

Chronicity rhetoric in health and welfare systems inhibits patient recovery: a qualitative, ethnographic study of fibromyalgia care.

Quantifying the Degree of Fatigue in People Reporting Symptoms of Post-COVID-19 Syndrome: Results from a Rasch Analysis.

Assessing the influence of lived-experience experts on healthcare providers in a virtual community of practice: a qualitative study.

Factors associated with having previously received a diagnosis of fibromyalgia, chronic fatigue syndrome and irritable bowel syndrome: A cross sectional DanFunD study.

[Systems thinking, subjective findings and diagnostic "pigeonholing" in ME/CFS: A mainly qualitative public health study from a patient perspective].

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After SARS-CoV-2 Infection.

Validity and diagnostic overlap of functional somatic syndrome diagnoses.

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