A helpful tool for combining patient symptoms, signs, and test results to generate differentials, accuracy of diagnostic tests, and more…

Over the past six weeks, I have been working some shifts in our new urgent care clinic. The fast pace and seemingly endless patients made me appreciate again the approach to the undifferentiated patient. For example, fever and a rash are common complaints seen in both adults and children in the UCC. Does that child have a simple viral exanthem, strep throat, or something a bit more exotic such as measles or even Ebola? Recent outbreaks in Washington and Congo along with easy and fast travel to virtually any place on earth makes these diagnoses unlikely but not impossible. Keeping a broad differential diagnosis is wise with just about any complaint, but can be especially useful when dealing with infectious diseases, cardiorespiratory, and neurologic complaints. Does that patient with a cough have an upper respiratory infection or pneumonia? Community-acquired pneumonia or Legionella or something even worse like Hantavirus or multi-drug resistant TB?

Previously at iMedicalApps, we reviewed several excellent decision-support tools including the outstanding IDdx: Infectious Disease Queries , the popular (and my go-to app for such things) VisualDx and the venerable, easy-to-use, Diagnosaurus.

The latest app to enter the market is called docLogica. The goal of the app is to aid providers in taking the undifferentiated patient by building an evidence-based differential diagnosis while providing quick access to the evidence-based statistics of common diagnostic tests, disease symptoms, and epidemiology on hundreds of diseases. The app was created by Dr. Michael Garfinkle, a Canadian internist/nephrologist. It helps providers of virtually any specialty, but especially those of us in primary care to easily recall the symptoms of combinations of symptoms for thousands (currently over 1600) diseases.

Evidence-based medicine

The app contains over 1600 disease symptoms, information on the accuracy of over 1100 diagnostic tests, and a nearly infinite number of differential diagnosis combinations all in the palm of your hand. The app is extremely well referenced with hyperlinks to PubMed articles for much of the included information. Disease prevalence for hundreds if not thousands of diseases are included along with information on the sensitivity, specificity, pre and posttest probabilities of diseases based upon signs/symptoms and diagnostic tests. The app is admittedly incomplete and the DDx Maker is labeled “beta” on the website so keep that in mind when using at the point of care.

What providers would benefit from docLogica?

Students, residents, nurses, mid-levels, family medicine, internal medicine, emergency medicine/urgent care, and any provider who wants some high-tech assistance in creating differentials or loves looking at statistics on disease accuracy.


  •  Free to download. Requires a $0.99/month subscription to unlock any functionality. The website is free.


  • Comprehensive collection of symptoms, signs, tests, and disease probabilities with sens/spec, pre-/posttest probabilities
  • Intuitive interface with rapid information retrieval plus hyperlinks to references
  • Available for Android


  • DDx Maker doesn’t seem to prioritize information on likelihood or frequency (lots of zebras for even common scenarios).
  • Layout of main page not optimized
  • Monthly subscription fee will be a barrier for some, but likely justified based on content


docLogica is a peek into the future of point-of-care apps that use “big data” and the wealth of medical literature to aid providers in the diagnosis and treatment of medical conditions. Although the app’s author clearly states its limitations, docLogica is a blast to use and contains thousands of helpful primers on tests, symptoms and can create a virtually endless combination of differentials similar to VisualDx (just not quite a fully developed yet). The only downside is the monthly subscription, but overall it’s likely still a bargain.

Overall Score

  • 4.5 stars

User Interface

  • 4.5 stars

The app has four main sections that can be navigated easily; while the DDx Maker can build robust differentials using information from the other sections. The Settings, Info, and Subscription info take up too much screen real estate and could be placed in a corner drop down menu for example.

Multimedia Usage

  • 4.5 stars

App contains thousands of symptoms, tests, disease probabilities which can be combined to generate differentials or viewed separately. Each area has hyperlinks to published articles on a particular subject.


  • 3.5 stars

App is free to download but requires a $0.99/month subscription to function.

Real-World Applicability

  • 4.5 stars

As algorithms and “big data” continue to improve and impact patient care, apps like docLogica will become increasingly popular with providers. Like IBM’s Watson, docLogica takes known information and applies it to the undifferentiated patient to help providers with diagnostic quandaries. Although far from perfect, I found the app helpful when used over the course of a week in an urgent care clinic to expand differentials and give some quick reference information about diseases and diagnostic tests.

Device Used For Review

  • iPhone 8 running iOS 12.1.2

Available for download for iPhone, iPad, and Android.

Disclaimer: The views expressed are those of the author(s) and do not reflect the official policy of the Department of the Army, the Department of Defense or the U.S. Government.