Message-ID: <3accdf3d-5f08-3dcb-af02-5b5288e54ab5@imbi.uni-freiburg.de>
Date: 2019-06-19T13:19:49Z
From: Gerta Ruecker
Subject: [R-meta] convergence in Mada
In-Reply-To: <CAMU7UxEX+G7qj2KyO+0CyCWmxociaNAgVJbE0GkgYECrM4cuQw@mail.gmail.com>
Dear Philipp,
Could you please give a link or full bibliographic details for the paper
you cited (Vogelsang et al., 2018)? I couldn't find it.
Best,
Gerta
Am 19.06.2019 um 14:59 schrieb 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 at 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]]
>>
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>>
>
--
Dr. rer. nat. Gerta R?cker, Dipl.-Math.
Institute of Medical Biometry and Statistics,
Faculty of Medicine and Medical Center - University of Freiburg
Stefan-Meier-Str. 26, D-79104 Freiburg, Germany
Phone: +49/761/203-6673
Fax: +49/761/203-6680
Mail: ruecker at imbi.uni-freiburg.de
Homepage: https://www.imbi.uni-freiburg.de/persons/ruecker/person_view