Can a consensus occur on a research case definition for ME/CFS?

Abstract

ABSTRACT Introduction: Many controversies have emerged around developing a consensus on a research case definition for ME and ME/CFS. To determine if there might be a consensus among patients, healthcare workers, and researchers, a brief questionnaire was distributed to an international group of patients to assess key issues involving ME and ME/CFS case definitions. Method: Respondents were asked questions about core symptoms and other critical case definition issues. Results: Overall, post-exertional malaise, cognitive impairment, fatigue, and unrefreshing sleep were the most endorsed core symptoms with at least 80% consensus among participants. Considerable support occurred for the ME-ICC (Myalgic Encephalomyelitis-International Consensus Criteria) and the Canadian Consensus Criteria (CCC), whereas the Fukuda Criteria received the least support. Items rated as important for a research case definition included the severity of the illness, onset type, duration of illness, illness course, exclusions, and comorbidities. Conclusions: The implications of these findings for developing a consensus on research case definition criteria are discussed.