Hello friends of R list,
Im a physician and Im not that good in statistics. I have posted similar
email in the epi-sig list but no one aswered so far. Im cunducting a
systematic review on two diagnostic test for a particular tropical disease.
I found a free software that make most of the analysis called MetaDiSc.
However there is a paticular analysis that I wuould like to try that it is
not implemented in this software. I looked in R for meta-analysis functions
but the packeges available dont work with diagnostic tests.
Im trying for a while to adapt in R a function develped in SAS and published
in "J.B. Reitsma et al. / Journal of Clinical Epidemiology 58 (2005)
982?990", wich is a bivariate approach to meta-analysis of diagnotic tests.
Since I do not have any experience with SAS, Im having a hard time trying to
do so.
There is an appendix at the original text with some step by step (in SAS
syntax) on how to do it but Im stuck on a more advanced stuff which I cant
find a solution. In a step it is mentioned a Van Houwelingen (Statist. Med.
2002; 21:589624) approach to incorporate between and within study variances
and using the restricted maximum likelihood estimation.
This is the script (or function) so far....
bivar<-function(TP,FP,FN,TN){
# find a way to sum 0.5 to each null cell if any
Se<-TP/(TP+FN)
Sp<-TN/(TN+FP)
logSe<-log(Se/(1-Se))
logSp<-log(Sp/(1-Sp))
vlogSe<-1/(Se*(1-Se)*(TP+FN))
vlogSp<-1/(Sp*(1-Sp)*(TN+FP))
bsvlogSp<-0
cblog<-0
bsvlogSp<-0
sdata<-rbind(bsvlogSp,cblog,bsvlogSp,vlogSe,vlogSp)
Does anyone know if there is any package or function with this bivariate
random effect model that I cuold try to use? Neither a I could find any
apckage or function to aply the restricted maximum likelihood estimation.
Any tip that helps me go on or hand in the development of this script
(function) would be most welcome.
Best regards to all,
--
Pedro Emmanuel Brasil
Instituto de Pesquisa Clinica Evandro Chagas
Fundação Oswaldo Cruz
Rio de Janeiro - Brasil
[EMAIL PROTECTED]
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