At 09:34 26/05/2014, Verena Weinbir wrote:
Hey guys,
I have tested the metafor trim and fill function (y:SD, x:SMD)on my data
set and yielded the following result:
1. missing studies on the right: 34
That seems a lot of missing studies unless you have a very large set
of primary studies.
2. open circles on the rights side appear to be the number of additional
effects
3. adjusted d would be higher than observed d.
Implying that the mechanism is suppressing studies which found a
large effect. This might happen if the dominant view is that there is
no effect and so when people find one they worry about their results.
Since normally, as I understand, those parameters are the other way round
(black dots indicating missing studies on the left, which would reduce the
effect size), I wonder:
Is there a mistake I have done? Or, if this is an actual outcome how can I
interpret this? That its not a publication bias that influences my data
set, but a lack of precision (studies missing that are precise -small SD-
and have big SMD)?
Sorry but that bit is not very clear to me.
Many thanks in advance!
Verena
[[alternative HTML version deleted]]
Michael Dewey
i...@aghmed.fsnet.co.uk
http://www.aghmed.fsnet.co.uk/home.html
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