[R] Meta-Analysis using lme

[Heike Heidemeier]

Dear list-members,

I am trying to use R to conduct a meta-analysis, i.e. I'd like to use a
multi-level model to integrate the findings of a number of primary research
studies. 
 
I set up a simple two level-model (only summary statistics are provided by
each study) as follows:

sapp.lme <- lme(D ~ 1, data = sapp.frame, random = ~ 1 | STUDYNR, 
weights=varFixed(~-1+STDERR_D),na.action = na.exclude)

The intercept is random on both levels and the variable stderr_D (the
sampling variance) is supposed to be random only on level one. Besides, I
need to constrain the variance of stderr_d to equal 1. 

Could anybody help me correct the code I provided? Thanks in advance for
your time.

Cheers, 
Heike Heidemeier



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