[R-meta] convergence in Mada

[CHAPPELL Francesca]

On a related note, it can also be useful to profile the likelihood of the correlation coefficient - estimation of correlation coefficient can be particularly poor even when convergence is achieved.

Francesca


-----Original Message-----
From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces using r-project.org] On Behalf Of Philipp Doebler
Sent: 19 June 2019 13:59
To: James Meyer <outlook_655291802F3BAFF3 using outlook.com>
Cc: r-sig-meta-analysis using r-project.org
Subject: Re: [R-meta] convergence in Mada

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
>
>
>         [[alternative HTML version deleted]]
>
> _______________________________________________
> R-sig-meta-analysis mailing list
> R-sig-meta-analysis using r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis
>


--
Prof. Dr. Philipp Doebler
Technische Universität Dortmund
Fakultät Statistik
Vogelpothsweg 87
44227 Dortmund

Tel.: +49 231-755 8259
Fax: +49 231-755 3918
doebler using statistik.tu-dortmund.de
www.statistik.tu-dortmund.de/1261.html


Wichtiger Hinweis: Die Information in dieser E-Mail ist vertraulich. Sie ist ausschließlich für den Adressaten bestimmt. Sollten Sie nicht der für diese E-Mail bestimmte Adressat sein, unterrichten Sie bitte den Absender und vernichten Sie diese Mail. Vielen Dank.
Unbeschadet der Korrespondenz per E-Mail, sind unsere Erklärungen ausschließlich final rechtsverbindlich, wenn sie in herkömmlicher Schriftform (mit eigenhändiger Unterschrift) oder durch Übermittlung eines solchen Schriftstücks per Telefax erfolgen.

Important note: The information included in this e-mail is confidential.
It is solely intended for the recipient. If you are not the intended recipient of this e-mail please contact the sender and delete this message. Thank you.
Without prejudice of e-mail correspondence, our statements are only legally binding when they are made in the conventional written form (with personal signature) or when such documents are sent by fax.

[[alternative HTML version deleted]]

_______________________________________________
R-sig-meta-analysis mailing list
R-sig-meta-analysis using r-project.org
https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis
The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.