[R] Unweighted meta-analysis

[Roy Sanderson]

Hello

I'm very much a beginner on meta-analysis, so apologies if this is a
trivial posting.  I've been sent a set data from separate experimental
studies, Treatment and Control, but no measure of the variance of effect
sizes, numbers of replicates etc.  Instead, for each study, all I have
is the mean value for the treatment and control (but not the SD).  As
far as I can tell, this forces me into an unweighted meta-analysis, with
all the caveats and dangers associated with it.  Two possible approaches
might be:

a) Take the ln(treatment/control) and perform a Fisher's randomisation
test (and also calculate +/- CI).
b) Regress the treatment vs control values, then randomise (with or
without replacement?) individual values, comparing the true regression
coefficient with the distribution of randomisation regression
coefficients.

Both approaches would appear to be fraught with risks; for example in
the regression approach, it is probable that the error distribution of
an individual randomised regression might not be normal - would this
then invalidate the whole set of regressions?

Many thanks for your advice.
Roy

-- 
Roy Sanderson
Institute for Research on Environment and Sustainability (IRES)
Devonshire Building
Newcastle University
Newcastle upon Tyne NE1 7RU
r.a.sanderson at newcastle.ac.uk
0191 246 4835