Margaret A.WinkerMD, Deputy EditorIndividualAuthorPhil B.FontanarosaMD, Interim CoeditorIndividualAuthor
Copyright 1999 American Medical Association.
All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.1999
To the Editor: As occupational
medicine specialists, we read with interest the suggestion of Dr
Garfinkel and colleagues1 that yoga may benefit patients
with CTS. Unfortunately, methodological flaws substantially limit
inferences drawn from this article. Among them is the authors' failure
to control for potential confounding of intervention efficacy by a
number of important variables. For example, 40% of the control and
23% of the comparison populations were men. The groups also differed
in baseline grip strength (controls, 183.9 mm Hg; intervention group,
161.6 mm Hg). The sex differential may account for the difference in
grip strength, or the results may be independent; either scenario might
affect treatment response and bias the results. Other uncontrolled
potential confounders include current treatment and CTS severity.
Without controlling for the effects of these potential confounders,
estimates of intervention efficacy may be biased.
Deitchman S, Gerr F. Yoga for Carpal Tunnel Syndrome. JAMA. 1999;281(22):2087-2089. doi:10-1001/pubs.JAMA-ISSN-0098-7484-281-22-jbk0609