Message-ID: <4599a36a-8322-3f34-6271-5ea15e345e4c@dewey.myzen.co.uk>
Date: 2023-07-12T14:09:07Z
From: Michael Dewey
Subject: [R-meta] Calculating standard errors from confidence interval and weights assigned
In-Reply-To: <CAH6EOcKwReJEUGA61MAAgsY0UoBKVCY5qpKJ2a26tHD+yeSUbw@mail.gmail.com>
Dear Win
If you fit a random-effects model then the weights become more nearly
equal tending to equality as tau^2 increases. I suspect that may be the
issue here.
Michael
On 12/07/2023 05:36, Win Thu via R-sig-meta-analysis wrote:
> Hello,
>
> I would like to seek your opinions on calculating standard error (sei)
> from confidence intervals, and weights assigned to each study in a
> random effects model.
> To include in rma function*rma(yi, sei, data)*, I used the following
> formula to calculate sei
>
> *sei <- [log(CI upper limit) - log(CI lower limit)] / 3.92 *
> For yi, it will be log(relative risk).
>
> Then, I have the following weights for each study, which I am not very
> confident as the studies with larger sample sizes (cohort studies) were
> given reduced weights compared to smaller studies (case-control).
> I need to combine both studies as there are limited studies on the topic.
>
> I am grateful for your?feedback.
>
> Untitled.png
> Thank you,
> Win
>
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--
Michael
http://www.dewey.myzen.co.uk/home.html