JAMA study may be misleading
This article is reprinted with permission from The CFS Research Review Vol. 2, No. 4 Fall 2001.
A review article in the Sept. 19, 2001 issue of the Journal of the American Medical Association states what most familiar with the chronic fatigue syndrome (CFS) literature already know: studies of treatments in CFS involve small numbers of participants, use inconsistent outcome measures and yield mixed results.
The authors have summarized the results of two government-funded analyses (one from the U.S. and the other from the U.K.) of the treatment literature, including published and unpublished reports of pharmacologic, behavioral and other therapies. Nineteen databases were searched, identifying 350 studies conducted between 1986 and 2000. Of those, 44 research reports were included in the review, representing a total of 2,801 patients.
Reviewers selected studies of pharmacologic interventions including hydrocortisone, fludrocortisone and galanthamine and immunological therapies such as immunoglobulin, Ampligen and interferon. Trials of supplements such as essential fatty acids and magnesium were evaluated, as were studies of massage and osteopathy. Research on two behavioral interventions, graded exercise therapy (GET) and cognitive behavioral therapy (CBT), accounted for nine of the 44 studies.
Comparison of the studies proved challenging. There were considerable differences in study design (36 employed randomized controlled trials and eight used controlled trials), outcome measures (more than 38 different outcomes were assessed), duration of treatment (ranging from two to 52 weeks) and length of follow-up (ranging from two weeks to five years).
The authors highlighted CBT and GET as the most promising therapies, although they acknowledge that these studies also had the highest dropout rates of the 44. Five of the nine behavioral studies used the less-restrictive Oxford criteria to select patients, and all, by design, only included patients who were well enough to frequently travel to clinic.
Positive effects of other therapies received less attention. Of those studies with relatively high validity scores, independent trials of immunoglobulin, hydrocortisone, magnesium and essential fatty acids showed benefits.
The reviewers conclude that greater standardization of studies is needed. They suggest that a classification system for illness severity be developed, as well as guidelines for the duration of intervention and follow-up. Finally, the authors prioritize agreement upon outcome measures as a necessary step to improve the comparability of CFS studies.
The complete report of the U.S. evidence based review summarized in the JAMA article is due from the Agency for Healthcare Research and Quality in late November or early December. The U.K. literature analysis is available on the Internet at www.york.ac.uk/inst/crd/cfs.htm.