Pulmonary hypertension

I have a question about how one chooses between 416.0 and 416.8? (I am a physician, and I was looking at trends in idiopathic PAH (416.0) hospitalizations and deaths.

I noticed that there was a dramatic decline in 416.0 hospital discharge diagnoses beginning in 2001, but then I looked at 416.8 and they went up by the same amount. So I think it is a coding thing, but I can't find a coding change.

Any thoughts? How do you decide what to default the term "pulmonary hypertension" without limited informatino to?

Thanks,
Kelly

Pulmonary HTN

416.0, Primary pulmonary hypertension
increased pressure with the the pulmonary circulation, usually secondary to cardiac or pulmonary disease.
416.8- Other chronic pulmonary heart diseases.
In coding the professional will assign the diagnosis code based on documentation. If the condition is not stated as primary pulmonary hypertension, but has another documented pulmonary heart disease (ex,Cor pulmonale, or pulmonary hypertension-secondary) , they will default to 416.8.

definitions

In the conventional classification, pulmonary hypertension, which is also called pulmonary arterial hypertension, is divided into two main categories; 1) primary pulmonary hypertension (not caused by any other disease or condition); and 2) secondary pulmonary hypertension (caused by another underlying condition). Secondary pulmonary hypertension is much more common than primary pulmonary hypertension. In the end, the coder assigns a code based on medical documentation, code 416.0 states "primary" and thus would be key word in code assignment.