Research bias in ME/CFS

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Research in every field deals with bias. Research into myalgic encephalomyelitis/chronic fatigue syndrome faces specific kinds of bias issues as it navigates significant gaps in scientific knowledge and several opposing viewpoints.[citation needed]

Emphasis on randomized controlled trials and systematic reviews[edit | edit source]

Following an Evidence-Based Medicine (EBM) model gives greater weight to systematic reviews and randomized controlled trials.[1]

PACE trial[edit | edit source]

Davenport et al. (2018) state the lack of randomized controlled trials in ME/CFS research mean that an evidence-based model can be unduly influenced by a very small number of studies, for example the PACE trial found that treating ME/CFS with graded exercise therapy or cognitive behavioral therapy did not result in clinically significant improvements - but this trial heavily influenced the clinical use of those treatments.[1] The PACE trial was so problematic that it was used an the example for Prof. Bruce Levin's presentation How Not To Conduct A Randomized Clinical Trial, and The Lancet received open letters signed by over 100 people, including researchers and academics, calling for the trial to be retracted.

Cochrane systematic review[edit | edit source]

The highly influential Cochrane review of exercise therapy for chronic fatigue syndrome was also found to have significant flaws.

Prevalence[edit | edit source]

Bias recognition[edit | edit source]

Geraghty et al. (2019) looked at evidence behind the popular cognitive behavioral model of ME/CFS, and found that a number of research papers contained significant evidence that did not support the model combined with contradictory abstracts or conclusions at odds with the authors' results,[2] and notable selective interpretation of evidence, such as ignoring any contradictory research.[2]

Sonia Lee (PhD, University of Sydney) assessed research waste in ME/CFS by comparing the PACE trial with two cellular trials, finding that "selective reporting", an indicator of research waste, was greater in the PACE trial; however this paper (2017) was not peer-reviewed.[3]

Nacul et al. (2017) discussed the effects of selection bias, highlighting how psychosocial/biopsychosocial studies frequently used the broadest diagnostic criteria - the Oxford criteria - and did not break results down by subgroup. The use of the Oxford criteria lead to a 100-fold increase in disease prevalence compared to the Canadian Consensus Criteria (CCC); with 14 out of 15 patients meeting the Oxford criteria typically failing to meet the Canadian Consensus Criteria for ME/CFS.[4]

Notable studies[edit | edit source]

  • 1982, Suffering and the Social Construction of Illness: The Delegitimation of Illness Experience in Chronic Fatigue Syndrome[5](Abstract)
  • 2017, How have selection bias and disease misclassification undermined the validity of myalgic encephalomyelitis/chronic fatigue syndrome studies?[4](Full text)

Articles and blogs[edit | edit source]

Possible causes[edit | edit source]

See also[edit | edit source]

Learn more[edit | edit source]

References[edit | edit source]

  1. 1.01.11.2 Davenport, Todd E; Stevens, Staci R; VanNess, J Mark; Stevens, Jared; Snell, Christopher R (Jul 17, 2018). "Checking our blind spots: current status of research evidence summaries in ME/CFS". British Journal of Sports Medicine: 1–2. doi:10.1136/bjsports-2018-099553. ISSN 0306-3674. 
  2. 2.02.12.2 Geraghty, Keith; Jason, Leonard; Sunnquist, Madison; Tuller, David; Blease, Charlotte; Adeniji, Charles (Jan 1, 2019). "The 'cognitive behavioural model' of chronic fatigue syndrome: Critique of a flawed model". Health Psychology Open. 6 (1): 2055102919838907. doi:10.1177/2055102919838907. ISSN 2055-1029. 
  3. 3.03.1 Lee, Sonia (May 7, 2017). "Research Waste in ME/CFS". bioRxiv: 133926. doi:10.1101/133926. 
  4. 4.04.1 Nacul, Luis; Lacerda, Eliana M; Kingdon, Caroline C; Curran, Hayley; Bowman, Erinna W (Mar 1, 2017). "How have selection bias and disease misclassification undermined the validity of myalgic encephalomyelitis/chronic fatigue syndrome studies?". Journal of Health Psychology: 1359105317695803. doi:10.1177/1359105317695803. ISSN 1359-1053. PMC 5581258Freely accessible. PMID 28810428. 
  5. Ware, Norma C. (Dec 1992). "Suffering and the Social Construction of Illness: The Delegitimation of Illness Experience in Chronic Fatigue Syndrome". Medical Anthropology Quarterly. 6 (4): 347–361. doi:10.1525/maq.1992.6.4.02a00030. ISSN 0745-5194. 
  6. Goudsmit, Ellen M; Stouten, Bart; Howes, Sandra (Oct 5, 2005). "Editorial bias in the Lancet". www.axfordsabode.org.uk. ME Research Online. Retrieved Apr 20, 2019. 
  7. Goudsmit, Ellen M.; Stouten, Bart (2011). "Editorial bias in the British Medical Journal". Journal of Chronic Fatigue Syndrome. 12 (4): 47–59. Retrieved Jan 23, 2019. 
  8. Goudsmit, Ellen M; Howes, Sandra (2017), "Bias, misleading information and lack of respect for alternative views have distorted perceptions of myalgic encephalomyelitis/chronic fatigue syndrome and its treatment", Journal of Health Psychology, 22 (9): 1159-1167, doi:10.1177/1359105317707216 
  9. Blease, Charlotte; Geraghty, Keith J. (Sep 2018). "Are ME/CFS Patient Organizations "Militant"? : Patient Protest in a Medical Controversy" (PDF). Journal of Bioethical Inquiry. 15 (3): 393–401. doi:10.1007/s11673-018-9866-5. ISSN 1176-7529. PMID 29971693. 
  10. Edwards, Jonathan (Mar 28, 2017). "PACE team response shows a disregard for the principles of science". Journal of Health Psychology. 22 (9): 1155–1158. doi:10.1177/1359105317700886. ISSN 1359-1053. The PACE trial of cognitive behavioural therapy and graded exercise therapy for chronic fatigue syndrome/myalgic encephalomyelitis has raised serious questions about research methodology. An editorial article by Geraghty gives a fair account of the problems involved, if anything understating the case. The response by White et al. fails to address the key design flaw, of an unblinded study with subjective outcome measures, apparently demonstrating a lack of understanding of basic trial design requirements. The failure of the academic community to recognise the weakness of trials of this type suggests that a major overhaul of quality control is needed. 
  11. Shepherd, Charles (Oct 12, 2017). "MEA Review: The SMILE trial – a lesson in how not to conduct clinical trials in people with ME/CFS". ME Association. Retrieved Apr 21, 2019. 

Bias - Bias in research is "a systematic deviation of an observation from the true clinical state".

Randomized controlled trial (RCT) - A trial in which participants are randomly assigned to two groups, with one group receiving the treatment being studied and a control or comparison group receiving a sham treatment, placebo, or comparison treatment.

ME/CFS - An acronym that combines myalgic encephalomyelitis with chronic fatigue syndrome. Sometimes they are combined because people have trouble distinguishing one from the other. Sometimes they are combined because people see them as synonyms of each other.

Bias - Bias in research is "a systematic deviation of an observation from the true clinical state".

Canadian consensus criteria (CCC) - A set of diagnostic criteria used to diagnose ME/CFS, developed by a group of practicing ME/CFS clinicians in 2003. The CCC is often considered to be the most complex criteria, but possibly the most accurate, with the lowest number of patients meeting the criteria. Led to the development of the International Consensus Criteria (ICC) in 2011.

Myalgic encephalomyelitis (ME) - A disease often marked by neurological symptoms, but fatigue is sometimes a symptom as well. Some diagnostic criteria distinguish it from chronic fatigue syndrome, while other diagnostic criteria consider it to be a synonym for chronic fatigue syndrome. A defining characteristic of ME is post-exertional malaise (PEM), or post-exertional neuroimmune exhaustion (PENE), which is a notable exacerbation of symptoms brought on by small exertions. PEM can last for days or weeks. Symptoms can include cognitive impairments, muscle pain (myalgia), trouble remaining upright (orthostatic intolerance), sleep abnormalities, and gastro-intestinal impairments, among others. An estimated 25% of those suffering from ME are housebound or bedbound. The World Health Organization (WHO) classifies ME as a neurological disease.

Myalgic encephalomyelitis (ME) - A disease often marked by neurological symptoms, but fatigue is sometimes a symptom as well. Some diagnostic criteria distinguish it from chronic fatigue syndrome, while other diagnostic criteria consider it to be a synonym for chronic fatigue syndrome. A defining characteristic of ME is post-exertional malaise (PEM), or post-exertional neuroimmune exhaustion (PENE), which is a notable exacerbation of symptoms brought on by small exertions. PEM can last for days or weeks. Symptoms can include cognitive impairments, muscle pain (myalgia), trouble remaining upright (orthostatic intolerance), sleep abnormalities, and gastro-intestinal impairments, among others. An estimated 25% of those suffering from ME are housebound or bedbound. The World Health Organization (WHO) classifies ME as a neurological disease.

Cognitive behavioral therapy (CBT) - A type of psychotherapy geared toward modifying alleged unhealthy thinking, behaviors or illness beliefs. One of the treatment arms used in the controversial PACE trial.

Graded exercise therapy (GET) - A gradual increase in exercise or activity, according to a pre-defined plan. Focuses on overcoming the patient's alleged unhelpful illness beliefs that exertion can exacerbate symptoms, rather than on reversing physical deconditioning. Considered controversial, and possibly harmful, in the treatment or management of ME. One of the treatment arms of the controversial PACE trial.

The information provided at this site is not intended to diagnose or treat any illness.
From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history.