This program calculates agreement indices and many medical diagnostic and decision-oriented indices for 2 x 2 classification tables (along with significance tests for the measures of agreement).

(20-Feb-05) I've upgraded the installation for compatibility with ME/2000/NT and for Windows XP (Pro and Home) - via Delphi 2005. The program otherwise remains the same with its on-line help file (35 pages!) and an increased display area.. It also contains hint information on every index computed - with a 10sec delay to allow you to read the extensive hint information. Just run the mouse cursor over an output cell, and the hint will appear. More extensive information is available in the on-line help. It is recommended as a teaching-support utility for students etc. Good for looking at "what-if" scenarios and the massive discrepancies that can sometimes be obtained between different measures of dichotomous agreement. Specifically, the program calculates the following measures of agreement from a 2x2 table (frequencies input by the user) - and now also displays the expected frequencies alongside the observed frequencies:

• Phi
• Phi/Phi Max
• Yule's Q (Gamma)
• Jaccard
• G-Index
• Bennett's B-index
• Kappa Interrater Reliability (agreement) - also includes an associated online HELP section with formula and formula reference.

and the following Medical Test Evaluation statistics:

• Sensitivity
• Specificity
• Kraemer's Quality Indices
• Positive Power of Prediction
• Negative Power of Prediction
• Prediction Efficiency/Classification Accuracy
• Relative Improvement Over Chance
• Base Rate/Prevalence
• Relative Risk
• Odds of Outcomes
• Odds Ratio
• False Positive Rate
• False Negative Rate
• Cohen's d (d-prime within ROC)
• Estimated r from d-prime

(7th July, 2006) Dichot 4 is finally being programmed - slow going because of forced career change. It now includes reverse-engineered analyses (input correlations or sensitivity and specificity and/or base rates and see what the counts look like in the table cells), ROC analysis, cost-benefit trade-off analysis, graphics, graphics file and Excel exports, and word-processor-ready formatted reports - with new and more comprehensive HTML help.

Download and Installation Information
Click here to download the zipped program. The zipped file is 4.0Mb in size and is named Dichot3_D2005_setup.zip.To install the Dichot3 software, save the Dichot3_D2005_setup.exe file to any temporary directory, then run it as you would any setup file; by default it will install to c:\dichot3