I've been looking at the levels of evidence on the CEBM site & found
that evidence from systematic reviews (SR) of RCTs is graded
depending on whether or not the heterogeneity was worrisome ie
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* By homogeneity we mean a systematic review that is free of
variations (heterogeneity) in the directions and degrees of results
between individual studies. Not all systematic reviews with
statistically significant heterogeneity need be worrisome, and not
all worrisome heterogeneity need be statistically significant. As
noted above, studies displaying worrisome heterogeneity should be
tagged with a "-" at the end of their designated level.
from
http://cebm.jr2.ox.ac.uk/docs/levels.html
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It seems to me that the assessment of worrisome heterogeniety is a
bit vague & subjective. Has anyone come across any examples where
this definition has been used?
Thanks
Valerie
Valerie Seagroatt
Unit of Health Care Epidemiology
Dept of Public Health and Primary Care
Institute of Health Sciences
Old Road
Oxford OX3 7LF
Telephone 01865 226868
Fax 01865 226993
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