[R-meta] convergence in Mada

[Philipp Doebler]

Hi James,

I have rarely had convergence problems. There are three potential problems:

(1) Low number of studies (5 model parameters...) but mada throws a warning
if I remember correctly.
(2) Little variance in the false positive rates and/or sensitivities.
Especially relevant if all studies have the same sensitivity of, say, 95%.
This can sometimes lead to a degenerate covariance matrix of the bivarate
random effect.
(3) A perfect between study correlation of logit(sens) and logit(fpr). If
there is any suspicion, calculate the correlation matrix with cov2cor.

Also have a look at all standard errors and confidence intervals. The
recent simulation study of Vogelsang et al. (2018) discusses convergence
issues of mada (and other packages).

Kind wishes,
   Philipp




On Wed, Jun 19, 2019 at 2:32 PM James Meyer <
outlook_655291802F3BAFF3 using outlook.com> wrote:

>
> How can you tell if convergence has been accomplished using the reitsma()
> function in mada ? Which package do you recommend using for DTA
> meta-analysis if you have a small number of studies?
>
> Sincerely
> James C Meyer
> Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for
> Windows 10
>
>
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-- 
Prof. Dr. Philipp Doebler
Technische Universität Dortmund
Fakultät Statistik
Vogelpothsweg 87
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Tel.: +49 231-755 8259
Fax: +49 231-755 3918
doebler using statistik.tu-dortmund.de
www.statistik.tu-dortmund.de/1261.html


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