Last data update: 2014.03.03

R: Computes post test probability to have a dissease based on...
fncEBMPostTestR Documentation

Computes post test probability to have a dissease based on the pre-test probability and the likelihood ratio of the diagnostic test


This dialog box permits you to define the probability of a patient to have a disease before performing a diagnostic test (pre-test probability), and the likelihood ratio of the diagnostic test. Based on these two, the post-test probability to actually have the disease is computed.

This is computed the following way:
pre-test odds <- pre-test probability / (1 - pre-test probability)
post-test odds <- pre-test odds * likelihood ratio
post-test probability<- post-test odds / (post-test odds + 1)


fncEBMPostTest(.pretest, .LR)



Pre-test probability.


Likekihood ratio of the diagnostic test.


The post-test probability of having the dissease.


Daniel-Corneliu Leucuta <>


fncEBMPostTest(.12, 5.7)


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

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> library(RcmdrPlugin.EBM)
Error in library(RcmdrPlugin.EBM) : 
  there is no package called 'RcmdrPlugin.EBM'
Execution halted