3-D Bar Graph of the Medical Data

This activity is a follow-up to the 2-D Medical Activity; if you have not completed that activity, please do so now. This activity contains the same data as the 2-D activity, but a second independent variable has been added. Thus, you will need to use a three-dimensional graphical analysis, specifically a bar graph, rather than a two-dimensional graphical analysis.

In this activity you will be analyzing the number of allowed services per CPT code for three different types of medical practices. The data were taken from 1996 patient records that were compiled by HCFA, which you learned about in the 2-D activity.

This data deals with current procedural terminology codes, also known as CPT codes. The five codes you will be using in this activity are known as Evaluation and Management (E&M) codes. E&M codes are a set of codes which are a subset of the CPT codes. Essentially, the codes 99201 through 99205 are the standard codes used for a patient's office encounter with a new doctor. These five codes do not represent a specific procedure, they merely describe the complexity of the office visit. For example, a visit labeled 99201 may be for a child with poison ivy -- not a very complex visit. 99205 may be used to describe the visit of an elderly man who suffers from a chronic respiratory ailment, hypertension, and skin problems -- a very complex visit. The codes are sent to insurance companies which have pre-determined the reimbursement for each code. The most common E&M code of the five we are dealing with is 99203. What do you think the graph will look like?

Using Excel (the TI-83 is not capable of producing 3-D graphs), generate a 3-D bar graph of the allowed services for each specialty, for each CPT code. Then answer the questions at the end of this page. This data exists in two files; one is in Excel Data format and one is in Text format.

What practice had the greatest number of allowed services for any CPT code? Does a pattern exist for the use of the five codes throughout all five medical practices? What does this pattern tell you?


Original work on this document was done by Central Virginia Governor's School students Jeremy Chapman, David Falwell, and Francie Webb (Class of '99).


Copyright © 1998 Central Virginia Governor's School for Science and Technology Lynchburg, VA