Spirometry question

At our Chronic Care Meeting, spirometry done in the office was discussed. One of the offices mentioned that they do spirometry when people are ill to see how sick they are at that time. I was under the impression that it was a test to be done when they were healthy to see if they have a condition and the severity of the condition. When I looked it up in the CPT book, it wasn't specific enough to say that doing it when they are ill is correct or incorrect for coding. Do you have any thought on this.

Medically

It can be done in both situations- for chronic state measurements and if ill to see degree of airflow restriction. The code is the same for both.

Spirometry question

Thank you for your input.