Journal of Medicine and Therapeutics`
chronic fatigue syndrome, epidemiology, case definitions
The Fukuda et al. criteria is the most widely used clinical case definition for diagnosing patients with chronic fatigue syndrome (CFS). Despite the frequency with which the Fukuda criteria are applied, the list of symptoms outlined in this case definition were not well enough specified to be easily applied to research settings. In 2005, Reeves et al. laid out a set of standards for operationalizing the Fukuda definition, specifying scales and cutoff scores for measuring the symptom criteria. This operationalization, often known as the empirical criteria, has been shown to identify an unexpectedly large number of patients, seemingly widening the net of inclusion for CFS diagnostic criteria. However, in a recent study in 2016 by Unger and colleagues it has been suggested that the 2005 Reeves et al. 2005 operationalization of the Fukuda criteria does not over-identify the number of patients with CFS as had been previously reported. This article reviews prior studies which provide context for these findings and offers a possible explanation for the discrepancies. Clearly, determining what case definition to use and how to operationalize it remains an important activity for scientists in this field, as it will influence work in multiple domains, including etiology, pathophysiology, epidemiology and treatment.
Jason, L.A., Gleason, K., & Fox, P. (2017). The implications of using a broad versus narrow set of criteria in research. Journal of Medicine and Therapeutics, 1(3), 1-6.