Knowledge Base Article

Q:

What are the determining factors for when a procedure is performed for diagnostic versus therapeutic purposes?

A:

First, determine the objective of the procedure.  Is the procedure performed to:  

• Make a diagnosis, or
• Eliminate a condition?

For example, a physician may remove all necrotic tissue that is present in a slow healing wound.  A sample of that tissue was sent to pathology to see what organisms may be growing. This would be a therapeutic removal of tissue as the objective was to remove all of the necrosis to promote wound healing.

Another example is found in Coding Clinic, Third Quarter 2017, page 12, which addresses the coding of abdominal paracentesis. The advice found here tells us to use the qualifier ‘Z’ if there is a therapeutic component to the procedure (0W9G3ZZ, Drainage of Peritoneal Cavity, Percutaneous Approach).  The physician may send a fluid sample to pathology to look for malignant cells or leukocytes. However, the objective of the paracentesis is to relieve the pain and discomfort from ascites, which is a therapeutic procedure.

It is important to note that if both a diagnostic and therapeutic paracentesis are performed separately, then both should be coded.

Biopsies are good examples of diagnostic procedures, such as, a pancreas biopsy in a patient with a pancreatic mass or bone marrow biopsy for unexplained anemia.