Bayesian software / BayesDiagnosticTests
BayesDiagnosticTests
Estimation of Disease Prevalence and the Parameters of One, Two or Three Diagnostic Tests



Install Instructions
BayesDiagnosticTests is a Perl program that was developed to calculate Bayesian marginal posterior distributions via Gibbs sampling for the prevalence of a disease, and sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios for each diagnostic test for that disease, in the absence of a gold standard. It was developed along the lines of our paper

Bayesian estimation of disease prevalence and the parameters of diagnostic tests in the absence of a gold standard
Joseph L, Gyorkos T , Coupal L
American Journal of Epidemiology 1995;141(3):263-272

and

Inferences for likelihood ratios in the absence of a gold standard
Joseph L, Gyorkos T
Medical Decision Making 1996; 16(4), pp. 412-417.

We recommend that you read these papers carefully before using this software.

The two free software packages listed below must be installed on your computer to use BayesDiagnosticTest: Any recent version of Strawberry Perl will do. Both packages install easily in a few minutes.

Microsoft Windows Script is also necessary but should already be sitting on your computer if you have a recent Windows operating system
(search for wscript.exe on your computer; if you can't find it, download it from the download section of Microsoft Windows Script webpage).

Once you have installed the necessary software, BayesDiagnosticTest is ready to run; see file InstructionManual.pdf for detailed instructions.

On first use, BayesDiagnosticTest will present a graphical user interface asking you to point to the most recent location of executable file WinBugs*.exe. When possible, path to the WinBugs executable file will be displayed as default value that you might want to use if it is indeed the most recent; if not, a browse button will allow you to indicate the actual executable file to use. Program may be slow to start when first run.


Avoiding trap errors from permission settings on Windows 7 and Windows Vista platforms
If you are working on a Windows 7 or Windows Vista platform and have run WinBUGS before, y ou may have already run into the cryptic Trap #060 error message illustrated to the right. This is due to restricted write permissions in c:\Program Files, where you may have installed WinBUGS.

WinBUGS must be installed in a directory where you have write permissions (e.g. in C:\Users\user name\Documents) for BayesDiagnosticTests to run smoothly.