This syntax works. Thanks very much.
Tiffany
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Tom Trikalinos
Sent: Monday, July 23, 2007 8:17 PM
To: [email protected]
Subject: Re: st: 'Meta' and 'Metareg' Coefficients & CIs Differ
I assumed that you have roger harbord's _metareg_ (>=v2.2.6 (?) -
10Dec2004). There was a previous version by stephen sharp... I do not
recall any specifics for the older command though.
tom
On 7/23/07, Tom Trikalinos <[email protected]> wrote:
> 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.
> >
> >
> > *
> > * For searches and help try:
> > * http://www.stata.com/support/faqs/res/findit.html
> > * http://www.stata.com/support/statalist/faq
> > * http://www.ats.ucla.edu/stat/stata/
> >
>
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
