This application lists over 400 laboratory tests, physical exam findings, history findings, and radiological studies for the most frequent diseases encountered in the primary care setting. For each entry, measures of the test’s efficacy found in the medical literature are reported. These metrics include: Sensitivity, Specificity, Positive Predictive Value, Negative Predictive Value, Positive Likelihood Ratio, and Negative Likelihood Ratio.

It also includes a calculator that will translate the Pre-test Probability into a Post-test
Probability in the event of either a positive or negative test result.

The database is categorized both by test and by disease. The tests are further divided into three categories: Laboratory, History/Physical Exam, and Radiology. The Pubmed entry where the data was found is listed with each result, along with a brief description of the paper.

A short explanation of the evidence-based metrics is also available in the Information

What's New

Version 2.0

New database update allows our team to keep data up-to-date. We also created a free website version at

Ratings and Reviews

AWD32 ,


Downloaded the app a little over a week ago, and have already used it more than a dozen times on the wards. Useful for checking how much confidence to place in a positive/negative test.

blo17 ,

All Good

We've updated and fixed a minor bug. This app is absolutely ready to start saving primary care physicians time and money. Simple, clean and easy to use. Enjoy!

Dancin Fan ,

They got it backwards, so it's misleading

This app appears to have a decent amount of data describing the sensitivity and specificity of diagnostic tests important to primary care physicians. Given the breadth of primary care, more diagnostic tests should be added over time with updates. The reason it only rates 2 stars is it has a major flaw - after you enter pre-test probability, it gives you the likelihood the patient does or does not have the disease tested for. But the numbers are backwards. The value given for the negative test result is actually the value for a positive result and vice versa. A better app to accomplish what this one attempts to do, but with less test data is Rx-Bayes (but Rx-Bayes allows you to add tests and test data to your personal app).


Lohr Designs LLC
19.8 MB
Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© Brett Lohr


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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