The chair wields significant power, and if he favours a majority decision, then he's likely to get a majority decision. The IOM uses a face-to-face meetings. Dr. Bateman describes their process: A Delphi-type process removes the interpersonal challenge: there is no face-to-face interaction; each participant is given time for thought and an equal opportunity to contribute; and in particular, disagreements are used to generate pooled information and increased understanding. Why would you challenge the International Consensus Panel's claim that “the authors, representing twelve countries, reached 100% consensus through a Delphi-type process?" I question whether the IOM Committee achieved 100% consensus based on Dr. Klimas' concurrent presentation to the P2P Panel. According to their report, the IOM Committee adapted a “GRADE grid” to facilitate its consensus discussions. The inconsistent application of the Committee's resulting conclusions provides a measure of the IOM consensus process. “The committee adapted a 'GRADE grid' to record individual judgments as to whether there is sufficient evidence that certain symptoms and abnormalities define either ME/CFS or a particular subtype of ME/CFS:” “The collated judgments were used to facilitate further discussion, which led to consensus among the committee members on final recommendations regarding diagnostic criteria;” “Conclusion: There is sufficient evidence that fatigue in ME/CFS is profound, not the result of ongoing excessive exertion, and not substantially alleviated by rest. This fatigue results in a substantial reduction or impairment in the ability to engage in pre-illness levels of occupational, educational, social, or personal activities and persists for more than 6 months;” “Conclusion: There is sufficient evidence that PEM is a primary feature that helps distinguish ME/CFS from other conditions;” “Conclusion: Despite the absence of an objective alteration in sleep architecture, the data are strong that the complaint of unrefreshing sleep is universal among patients with ME/CFS when questions about sleep specifically address this issue. While PSG is not required to diagnose ME/CFS, its use to screen for treatable sleep disorders when indicated is appropriate. Diagnosis of a primary sleep disorder does not rule out a diagnosis of ME/CFS;” “Conclusion: There is sufficient evidence that slowed information processing is common in patients with ME/CFS, and a growing body of evidence shows that it may play a central role in overall neurocognitive impairment associated with the disease. Such a deficit may be responsible for the disability that results in loss of employment and loss of functional capacity in social environments;” “Conclusion: Sufficient evidence indicates a high prevalence of orthostatic intolerance in ME/CFS, as measured by objective heart rate and blood pressure abnormalities during standing or head- up tilt testing or by patient-reported exacerbation of orthostatic symptoms with standing in day-to-day life. These findings indicate that orthostatic intolerance is a common and clinically important finding in ME/CFS;” “Conclusion: The committee elected not to include pain as a required element of its recommended diagnostic criteria for ME/CFS:” “Conclusion: Sufficient evidence supports the finding of immune dysfunction in ME/CFS:” “Conclusion: Evidence is insufficient to conclude that any specific neuroendocrine abnormalities cause ME/CFS, or that any such abnormalities either uniformly differentiate those with ME/CFS from individuals with other illnesses or distinguish a subset of ME/ CSF patients;” “Conclusion: There is sufficient evidence suggesting that ME/CFS follows infection with EBV and possibly other specific infections;” “Conclusion: There is sufficient evidence that orthostatic intolerance and autonomic dysfunction are common in pediatric ME/CFS; that neurocognitive abnormalities emerge when pediatric ME/CFS patients are tested under conditions of orthostatic stress or distraction; and that there is a high prevalence of profound fatigue, unrefreshing sleep, and post-exertional exacerbation of symptoms in these patients. There also is sufficient evidence that pediatric ME/CFS can follow acute infectious mononucleosis and EBV.” By what consistent criteria were core symptoms differentiated from symptoms not considered core? What happened in this process to the identification of subtypes?