In the absence of covariates _metareg_ does a random effects
meta-analysis, indeed.
However, with a different method than _meta_ (using the default
settings for _metareg_):
_metareg_ uses REML to get the tau^2 estimate (between study variance)
_meta_ is using the DerSimonian and Laird method
To get the same results use the following syntax:
metareg beta , wsse(SE) mm z
where mm--> uses the method-of-moments estimate for tau^2, aka the
DerSimonian and Laird method
z --> uses the z and not the t disrtibution to get the SE and the CIs
tom
On 7/23/07, Tiffany Davenport <[email protected]> wrote:
> I am using the 'meta' and 'metareg' commands for meta-analysis in Stata. As
> I understand it (and as previously posted) the pooled random effects
> estimate obtained by using the 'meta' command should be the same as the
> constant obtained in meta-regression analysis ('metareg') of a model with no
> covariates. I am finding that the values of these estimates as well as
> their confidence intervals differ slightly. I have entered the following
> syntax:
>
> "meta beta SE" - for the meta command and
>
> "metareg beta, wsse(SE)" for the meta-regression command
>
> 1. Shouldn't the pooled random effects estimate from 'meta' be the same as
> the coefficient for the constant from 'metareg,' and shouldn't the
> confidence intervals be the same? If not, I would appreciate any insight
> into why the two commands would generate different estimates with different
> standard errors. Are they weighted differently? Are adjustments to the
> syntax of either command necessary to ensure the intercepts and confidence
> intervals match?
>
> 2. Is it possible to display more decimal places in the 'meta' output?
>
> Thanks very much for any help.
>
>
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>
