The importance of a research case definition

ABSTRACT

All scientific activities with diseases rely on the selection of reliable and valid case definitions in order to accurately estimate prevalence rates, to identify biological markers, and to understand the outcomes of treatment trials. The failure to develop a consensus on which research case definition to use for defining Myalgic Encephalomyelitis (ME) and chronic fatigue syndrome (CFS) has had negative consequences for the scientific and patient community. If case definition criteria inappropriately select patients with symptoms due to primary affective disorders, other fatiguing medical conditions, burnout, or over-committed lifestyle issues, the scientific consequences are serious. For example, a case definition that is too broad would include individuals with other illnesses and conditions, complicating the tasks of estimating prevalence rates or identifying effective treatment programs. A consensus on a research case definition and its operationalization and assessment would enable investigators to select more homogenous samples that could expedite the identification of valid biological markers, and consequently reduce misperceptions regarding the role of psychogenic versus biomedical factors. Our editorial reviews the implications of previous research and clinical case definitions in CFS and ME domains.

KEYWORDS:

• Case definitions
• myalgic encephalomyelitis
• chronic fatigue syndrome
• diagnositic criteria

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Leonard A. Jason

Leonard A. Jason is a Professor of Psychology and Director of the Center for Community Research at DePaul University.

Pamela A. Fox

Pamela A. Fox is the Project Director at DePaul University for a NIH funded study involved in estimating the prevalence of ME and CFS among youth in a community-based study.

Kristen D. Gleason

Kristen D. Gleason is a Project Director at DePaul University for NIH-funded study on a prospective longitudinal study of mono among college students.