BACKGROUND: Current case definitions for myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) require an individual to report a 'substantial reduction' in activity levels, when compared to premorbid functioning. However, little guidance is provided on how to measure these reductions, as well as what level of reduction should be deemed 'substantial,' leading to inconsistencies in how this criterion is applied across research settings. PURPOSE: The current study examined the influence of substantial reduction criterion on case definitions. METHOD: The current study analyzed an international convenience sample of 1002 individuals with ME or CFS, 53 healthy controls, and 260 controls with other chronic illnesses. RESULTS: Findings indicated that the utility of the substantial reduction criterion varied by case definition, with more stringent case definitions not needing this criterion to identify cases. CONCLUSION: These results suggest that the requirement of a substantial reduction in functioning may be redundant when case definitions specify that individuals must endorse a set of core symptoms at specified frequency and severity levels.
BACKGROUND: Current case definitions for myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) require an individual to report a 'substantial reduction' in activity levels, when compared to premorbid functioning. However, little guidance is provided on how to measure these reductions, as well as what level of reduction should be deemed 'substantial,' leading to inconsistencies in how this criterion is applied across research settings. PURPOSE: The current study examined the influence of substantial reduction criterion on case definitions. METHOD: The current study analyzed an international convenience sample of 1002 individuals with ME or CFS, 53 healthy controls, and 260 controls with other chronic illnesses. RESULTS: Findings indicated that the utility of the substantial reduction criterion varied by case definition, with more stringent case definitions not needing this criterion to identify cases. CONCLUSION: These results suggest that the requirement of a substantial reduction in functioning may be redundant when case definitions specify that individuals must endorse a set of core symptoms at specified frequency and severity levels.
Authors: Paul A Harris; Robert Taylor; Robert Thielke; Jonathon Payne; Nathaniel Gonzalez; Jose G Conde Journal: J Biomed Inform Date: 2008-09-30 Impact factor: 6.317
Authors: Diana Ohanian; Abigail Brown; Madison Sunnquist; Jacob Furst; Laura Nicholson; Lauren Klebek; Leonard A Jason Journal: Neurology (ECronicon) Date: 2016-12-19
Authors: Alan J Thompson; Brenda L Banwell; Frederik Barkhof; William M Carroll; Timothy Coetzee; Giancarlo Comi; Jorge Correale; Franz Fazekas; Massimo Filippi; Mark S Freedman; Kazuo Fujihara; Steven L Galetta; Hans Peter Hartung; Ludwig Kappos; Fred D Lublin; Ruth Ann Marrie; Aaron E Miller; David H Miller; Xavier Montalban; Ellen M Mowry; Per Soelberg Sorensen; Mar Tintoré; Anthony L Traboulsee; Maria Trojano; Bernard M J Uitdehaag; Sandra Vukusic; Emmanuelle Waubant; Brian G Weinshenker; Stephen C Reingold; Jeffrey A Cohen Journal: Lancet Neurol Date: 2017-12-21 Impact factor: 44.182
Authors: Kristen D Gleason; Jamie Stoothoff; Damani McClellan; Stephanie McManimen; Taylor Thorpe; Ben Z Katz; Leonard A Jason Journal: Int J Behav Med Date: 2018-08