[R-meta] convergence in Mada
Hi Gerta, the paper appeared in Methods Inf Med: Vogelgesang F, Schlattmann P, Dewey M (2018). The Evaluation of Bivariate Mixed Models in Meta-analyses of Diagnostic Accuracy Studies with SAS, Stata and R. Methods Inf Med. 2018 May;57(3):111-119. doi: 10.3414/ME17-01-0021. Kind wishes, Philipp On Wed, Jun 19, 2019 at 3:19 PM Gerta Ruecker <ruecker at imbi.uni-freiburg.de> wrote:
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
Prof. Dr. Philipp Doebler Technische Universit?t Dortmund Fakult?t Statistik Vogelpothsweg 87 44227 Dortmund Tel.: +49 231-755 8259 Fax: +49 231-755 3918 doebler at statistik.tu-dortmund.de www.statistik.tu-dortmund.de/1261.html Wichtiger Hinweis: Die Information in dieser E-Mail ist vertraulich. Sie ist ausschlie?lich f?r den Adressaten bestimmt. Sollten Sie nicht der f?r 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 Erkl?rungen ausschlie?lich final rechtsverbindlich, wenn sie in herk?mmlicher Schriftform (mit eigenh?ndiger Unterschrift) oder durch ?bermittlung eines solchen Schriftst?cks 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]]