Leonard Jason and his team keep plugging away at the problems with the CDC Reeves / empirical definition and the cohorts it produces, a la Wichita and Georgia cohorts used in the CDC's XMRV paper.
Some of the major criticisms related to the Reeves definition concern its choice of subscales of the SF-36, and cutoff scores on those subscales, to determine whether a person has the substantial reduction in activity to be characterized as CFS. It uses a score relating to emotions (versus physical or social functioning, for example) as one of the relevant subscales, and uses arbitrary cutoffs, among other things.
In the abstract cited below, Jason says the Role Emotional subscale had the least sensitivity and specificity of all the subscales. Other findings also sound interesting.
Does anyone have access to the whole paper? I'd be interested in how else their findings differ from what the CDC is doing.
The problem is, the CDC should have done something like this before it published any results using the Reeves criteria.
http://www.ncbi.nlm.nih.gov/pubmed/20617920
Disabil Rehabil. 2010 Jul 9. [Epub ahead of print]
Measuring substantial reductions in functioning in patients with chronic fatigue syndrome.
Jason L, Brown M, Evans M, Anderson V, Lerch A, Brown A, Hunnell J, Porter N.
Center for Community Research, DePaul University, Chicago, IL 60614, USA.
Abstract
Purpose. All the major current case definitions for chronic fatigue syndrome (CFS) specify substantial reductions in previous levels of occupational, educational, social, or personal activities to meet criteria. Difficulties have been encountered in operationalizing 'substantial reductions.' For example, the Medical Outcomes Study Short Form-36 Health Survey (SF-36) has been used to determine whether individuals met the CFS disability criterion. However, previous methods of using the SF-36 have been prone to including people without substantial reductions in key areas of physical functioning when diagnosing CFS. This study sought to empirically identify the most appropriate SF-36 subscales for measuring substantial reductions in patients with CFS. Method. The SF-36 was administered to two samples of patients with CFS: one recruited from tertiary care and the other a community-based sample; as well as a non-fatigued control group. Receiver operating characteristics were used to determine the optimal cutoff scores for identifying patients with CFS. Results. The SF-36 Role-Emotional subscale had the worst sensitivity and specificity, whereas the Vitality, Role-Physical, and Social Functioning subscales had the best sensitivity and specificity. Conclusion. Based on the evidence from this study, the potential criteria for defining substantial reductions in functioning and diagnosing CFS is provided.
PMID: 20617920 [PubMed - as supplied by publisher]
Some of the major criticisms related to the Reeves definition concern its choice of subscales of the SF-36, and cutoff scores on those subscales, to determine whether a person has the substantial reduction in activity to be characterized as CFS. It uses a score relating to emotions (versus physical or social functioning, for example) as one of the relevant subscales, and uses arbitrary cutoffs, among other things.
In the abstract cited below, Jason says the Role Emotional subscale had the least sensitivity and specificity of all the subscales. Other findings also sound interesting.
Does anyone have access to the whole paper? I'd be interested in how else their findings differ from what the CDC is doing.
The problem is, the CDC should have done something like this before it published any results using the Reeves criteria.
http://www.ncbi.nlm.nih.gov/pubmed/20617920
Disabil Rehabil. 2010 Jul 9. [Epub ahead of print]
Measuring substantial reductions in functioning in patients with chronic fatigue syndrome.
Jason L, Brown M, Evans M, Anderson V, Lerch A, Brown A, Hunnell J, Porter N.
Center for Community Research, DePaul University, Chicago, IL 60614, USA.
Abstract
Purpose. All the major current case definitions for chronic fatigue syndrome (CFS) specify substantial reductions in previous levels of occupational, educational, social, or personal activities to meet criteria. Difficulties have been encountered in operationalizing 'substantial reductions.' For example, the Medical Outcomes Study Short Form-36 Health Survey (SF-36) has been used to determine whether individuals met the CFS disability criterion. However, previous methods of using the SF-36 have been prone to including people without substantial reductions in key areas of physical functioning when diagnosing CFS. This study sought to empirically identify the most appropriate SF-36 subscales for measuring substantial reductions in patients with CFS. Method. The SF-36 was administered to two samples of patients with CFS: one recruited from tertiary care and the other a community-based sample; as well as a non-fatigued control group. Receiver operating characteristics were used to determine the optimal cutoff scores for identifying patients with CFS. Results. The SF-36 Role-Emotional subscale had the worst sensitivity and specificity, whereas the Vitality, Role-Physical, and Social Functioning subscales had the best sensitivity and specificity. Conclusion. Based on the evidence from this study, the potential criteria for defining substantial reductions in functioning and diagnosing CFS is provided.
PMID: 20617920 [PubMed - as supplied by publisher]