The Chronic Fatigue Initiative (CFI) was an organization created and funded by the Hutchins Family Foundation to drive wide-scale research into the underlying infectious, immunological, and toxicological causes of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). CFI's goal was to disseminate its research findings to better equip the broader research community to work on mechanisms of ME/CFS and associated diagnostics, treatment, and prevention.
From 2011 to 2013, CFI conducted a large U.S. multicenter cross-sectional study to compare adults with ME/CFS from five geographically distinct clinical research sites with sex and geographic location (within 100 miles of the clinical location) matched control participants. To be eligible for study inclusion, ME/CFS participants had to have a diagnosis of ME/CFS from an expert clinician that met one or both internationally recognized case definitions: the 1994 Fukuda criteria (Fukuda et al., 1994) or the 2003 Canadian criteria (Carruthers et al., 2003) with expansion by Jason et al. (2010). A total of 401 study participants (201 ME/CFS cases, 200 controls) are included in the database, having contributed questionnaire, medical record, physical exam, and laboratory data, in addition to a wide range of biological specimens (RNA, DNA, plasma, serum, peripheral blood mononuclear cells, saliva, tears, and urine). The following table displays the number of ME/CFS participants and control participants by sex. For more information on CFI study participant recruitment, data collection, and findings, see Klimas et al. (2015).