I agree with Brian that this is an attempt to develop a subgroup analysis
The caution that is appropriate for any investigation which reports an
unplanned subgroup analysis
is that it is likely that the original design was not powered on the
subgroup level. That is, original
sample size, effect size and power were predicated on the overall sample
not on individual subgroups.
And, as I hope we all know, post-hoc power analysis is not very reliable.
It is relatively easy to predict behavior of large groups given prior
information on their behavior.
Even so, it is very difficult to predict the behavior of a single
individual within the group even given prior information on the group
behavior.
This seems to be an interested mathematical curiosity with little clinical
implication for individual patients.
William D. Grant, Ed.D.
Executive Director, Center for Emergency Preparedness
Professor, Emergency Medicine
SUNY Upstate Medical University
750 E. Adams St. EmStat
Syracuse, NY 13210
315-464-4365 (p) 315-464-6220 (f)
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>>> Brian Alper MD <[log in to unmask]> 3/22/2009 7:36 AM >>>
On the first read it sounds like a very sophisticated method for
subgroup analyses.
To some degree subgroup analyses help suggest better fits between the
data and subsets of patient populations.
Taken to the extreme (finding the single person in the data that is most
like your patient) would be like using a case report.
Sounds like there could be some discovery from the methods described but
it is hard to picture how it would replace our current methods for
accepting scientific research and applying it to patients.
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________________________________
From: Evidence based health (EBH)
[mailto:[log in to unmask]] On Behalf Of Rakesh Biswas
Sent: Sunday, March 22, 2009 6:05 AM
To: [log in to unmask]
Subject: A recent article for your comments
http://www.casesjournal.com/casesjournal/article/view/5051/103
would be grateful for your comments.
rakesh
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