Cost

One assembles clinical findings (signs, symptoms and history) before proceeding to lab tests.  This is encapsulated in the software by having separate tabs for clinical findings and tests.  But even when one moves to testing, one takes cost into account and begins with less expensive tests, particularly those with results that are known quickly.

Example to work through

Consider a 50-year-old woman with diarrhea, weight loss and anemia, with no history of travel to areas with poor sanitation.  On the Add Tests tab the less expensive tests are high in the list and expensive tests such as a colonoscopy are low. 

Initial recommendation of inexpensive tests (click the image to jump into the software)

Serum albumin was low, C-reactive protein was high and stool occult blood was negative (note that in the Phenotype tab the green number for pertinent positive findings has risen by 2 and the red number for pertinent negative findings has risen by 1). Including this information pushes the diagnosis towards inflammatory bowel diseases and now some more expensive tests are recommended to zero in on the diagnosis:

Later, more expensive tests are recommended (click the image to jump into the software)

The next steps were colonoscopy and upper gastrointestinal endoscopy, which confirmed the diagnosis of Crohn disease. 

The error associated with not paying attention to the cost of tests helps would be wasting money in medical care, reducing the availability for funds that can be used in more effective ways.