Pre- and post-test probabilities

Pre- and post-test probabilities

An interactive version of Coulthard and Coulthard (2019)'s leaf plot as a way of presenting the value of diagnostic tests accounting for uncertainty in the sensitivity and specificity of the test procedure.

Click the refresh button to run the analysis using the settings entered below. It may take some time for results to be displayed since a simulation approach is used to return credible interval estimates. Keep an eye on the progress indicator at the bottom right hand corner of the screen.

Pre-test probability of outcome

Plot for outcome

Positive Negative

Diagnostic test sensitivity

Estimate

Lower CI

Upper CI

Diagnostic test specificity

Estimate

Lower CI

Upper CI

Confidence intervals

Magnitude of CI for Se and Sp entered by user

Se and Sp CIs entered by user calculated using which method?

Magnitude of CrI for post-test probabilities

Decimal places for output

References
Coulthard MG, Coulthard T (2019) The leaf plot: a novel way of presenting the value of tests. British Journal of General Practice. DOI: 10.3399/bjgp19X702113

Haskins R, Osmotherly P, Tuyl F, Rivett D, (2014) Uncertainty in clinical prediction rules: The value of credible intervals. Journal of Orthopaedic and Sports Physical Therapy 44: 85 - 91. DOI: 10.2519/jospt.2014.4877

Stevenson M, Nunes T, Heuer C, Marshall J, Sanchez J, Thornton R, Reiczigel J, Robison-Cox J, Sebastiani P, Solymos P, Yoshida K, Jones G, Pirikahu S, Firestone S, Kyle R (2025) epiR: Tools for the Analysis of Epidemiological Data. R package version 2.0-87. DOI: 10.32614/CRAN.package.epiR

Veterinary Epidemiology @ Melbourne: https://mvs.unimelb.edu.au/ve@m/