Tag: CDC 1994 criteria

Chronic fatigue in a population sample: definitions and heterogeneity

Abstract:

BACKGROUND: Numerous nosological decisions are made when moving from the common human symptom of unusual fatigue to the rare chronic fatigue syndrome (CFS). These decisions have infrequently been subjected to rigorous evaluation.

METHOD: We obtained telephone interview data on fatiguing symptoms from 31406 individuals twins in the Swedish Twin Registry aged 42-64 years; 5330 subjects who endorsed fatigue and possessed no exclusionary condition formed the analytic group. We evaluated the definition and classification of CFS-like illness using graphical methods, regression models, and latent class analysis.

RESULTS: Our results raise fundamental questions about the 1994 Centers for Disease Control criteria as (1) there was no empirical support for the requirement of four of eight cardinal CFS symptoms; (2) these eight symptoms were not equivalent in their capacity to predict fatigue; and (3) no combination of symptoms was markedly more heritable. Critically, latent class analysis identified a syndrome strongly resembling CFS-like illness.

CONCLUSIONS: Our data are consistent with the ‘existence’ of CFS-like illness although the dominant nosological approach captures population-level variation poorly. We suggest that studying a more parsimonious case definition – impairing chronic fatigue not due to a known cause – would represent a way forward.

 

Source: Sullivan PF, Pedersen NL, Jacks A, Evengård B. Chronic fatigue in a population sample: definitions and heterogeneity. Psychol Med. 2005 Sep;35(9):1337-48. http://www.ncbi.nlm.nih.gov/pubmed/16168156

 

The specificity of the CDC-1994 criteria for chronic fatigue syndrome: comparison of health status in three groups of patients who fulfill the criteria

Abstract:

PURPOSE: The Centers for Disease Control (CDC)-1994 definition of chronic fatigue syndrome (CFS) is very broad, and there have been suggestions that it lacks specificity. To test this, we have compared three groups of patients, all of whom fulfill the criteria but self-report different etiologies.

METHODS: Patients with self-reported symptoms which developed sporadically (sCFS, n=48); after Gulf War service (GW, n=24); and following exposure to organophosphate insecticides (OP, n=25) underwent a clinical examination, completed the MOS SF-36 quality of life and Hospital Anxiety and Depression scales, and were assessed for major and minor criteria for CDC-1994 CFS.

RESULTS: Significant differences in simple clinical measures and outcome measures were observed between groups. The GW group had significantly more severe physical symptoms-fatigue, muscle and multi-joint pain-than OP or sCFS, and the sCFS group was significantly less impaired than the other two groups in terms of role emotional and mental health. In all three groups, a majority of patients exhibited muscle weakness in the lower limbs, and significant numbers of patients had absent or abnormal reflexes.

CONCLUSIONS: Differences in simple, easily performed clinical outcome measurements can be observed between groups of patients, all of whom fulfill the CDC-1994 criteria for CFS. It is likely that their response to treatment may also vary. The specificity of the CFS case definition should be improved to define more homogeneous groups of patients for the purposes of treatment and research.

 

Source: Kennedy G, Abbot NC, Spence V, Underwood C, Belch JJ. The specificity of the CDC-1994 criteria for chronic fatigue syndrome: comparison of health status in three groups of patients who fulfill the criteria. Ann Epidemiol. 2004 Feb;14(2):95-100. http://www.ncbi.nlm.nih.gov/pubmed/15018881