From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history
(Redirected from Empirical definition)
- Having greater than or equal to 4 symptoms set forth in the 1994 Fukuda criteria.
- Severe fatigue as determined using the Multidimensional Fatigue Inventory (MFI): score of greater than or equal to 13 on the general fatigue subscale or greater than or equal to 10 on the reduced activity subscale.
- Functional impairment as determined using the Short-Form 36 (SF-36): score of less than or equal to 70 physical function subscale, or less than or equal to 50 on role physical subscale, or less than or equal to 75 on social function subscale, or less than or equal to 66.7 on emotional subscale.
- Symptom validity as determined using the Centers for Disease Control Symptom Inventory: score of greater than or equal to 25 on the Symptom Inventory Case Definition subscale.
- There is no Post-exertional malaise (PEM) symptom. When there is no mandatory PEM it will be a Chronic Fatigue (a symptom of many illnesses, diseases, depression, medications) study, NOT a study of Chronic Fatigue Syndrome (a grossly misnamed disease).
- Letter by Tom Kindlon criticising the criteria, "Criteria used to define chronic fatigue syndrome questioned", that was published in Psychosomatic Medicine 
- One research study found 38% of those with a diagnosis of a Major depressive disorder were misclassified as having CFS using the empirical/Reeves definition.
Petition with over 2600 signatures (as of February 2016) against the criteria. 
- Reeves, W. C.; Wagner, D.; Nisenbaum, R.; Jones, J. F.; Gurbaxani, B.; Solomon, L.; Papanicolaou, D. A.; Unger, E. R.; Vernon, S. D.; Heim, C. (2005), "Chronic Fatigue Syndrome – A clinically empirical approach to its definition and study", BMC Medicine, 3 (19), doi:10.1186/1741-7015-3-19