Part B Insider (Multispecialty) Coding Alert

Published on Sat Apr 15, 2006 PDF

Key:  Learn the difference between malignant, benign and unspecified

When coding for hypertension, precise documentation and understanding primary vs. secondary are crucial. Follow these dos and don'ts to acquire accurate claims every time.

Do Check Documentation First

If your physicians are in the habit of merely writing "hypertension" on a patient's medical record, then you should point this problem out to him or her.

"The real key to correct coding for hypertension lies with physician documentation, and we need to educate our physicians to tell us explicitly" what type of hypertension they're treating, says Charla Prillaman, CPC, CHCO, director of physician compliance for Carolinas Healthcare System in Charlotte, NC. Physicians need to state the details of the patient's hypertension in the medical record, she adds.

Coding for hypertension "really comes down to documentation," agrees Jaime Darling, CPC, a coder with Graybill Medical Group in Escondido, CA. Often physicians will simply write "hypertension" in the diagnosis portion of their notes, which leads a coder to  401.9 (Essential hypertension; unspecified), she says. Explain to your physicians that adequate information for medical purposes isn't always adequate for coding purposes.

Action: Ask your physician  to indicate whether a patient's hypertension is malignant or benign, and also to define how any other manifestations are related to the hypertension. For example, the physician shouldn't just document hypertension and renal disease, but should indicate if the patient's hypertension is causing renal disease or if the renal disease is causing hypertension.

Watch for: If a patient has an elevated blood pressure reading, it doesn't mean the patient has hypertension. You should not assign a code for hypertension based on an abnormal finding without physician documentation. In this case, you would report 796.2 (Elevated blood pressure reading without diagnosis of hypertension) rather than a code from category 401, according to the AHA Coding Clinic 2005.

Don't Assume Benign By Default

When your physician doesn't provide information on whether the hypertension is malignant or benign, you shouldn't automatically assume she means benign.

The hypertension table in the ICD-9-CM manual's Index lists three possible categories into which hypertension may fall: malignant, benign and unspecified. The fourth digit of the hypertension category you report will differ depending on which category you choose.

Here's the breakdown for the essential and secondary hypertension codes:

• 401.0 (Essential hypertension, malignant)
• 401.1 (Essential hypertension, benign)
• 401.9 (Essential hypertension, unspecified)
• 405.0 (Secondary hypertension, malignant)
• 405.1 (Secondary hypertension, benign)
• 405.9 (Secondary hypertension, unspecified)

What to look for: "A patient has malignant hypertension when he or she has a recent significant increase over baseline blood pressure that is associated with target organ damage. There is usually vascular damage on funduscopic examination, such as flameshaped hemorrhages or soft exudates," says Jerome Williams, Jr., MD, FACC, a cardiologist with Mid Carolina Cardiology in Charlotte, NC. To diagnose malignant hypertension, papilledema must be present, Williams says. Up to one percent of patients with benign hypertension may develop malignant hypertension--meaning malignant hypertension can be life threatening and may cause stroke but is much less common than benign hypertension.

Common assumption: Because benign hypertension is more common, physicians often assume they are indicating benign hypertension when they simply write "hypertension," Prillaman explains. But if the documentation doesn't specifically state "benign" or "malignant," the only accurate choice you have is to report an unspecified code, she adds.

Do Move Beyond Malignant And Benign

Identifying whether the hypertension is benign or malignant won't tell your payors the whole story.

You've got to also show whether the hypertension is primary or secondary to the patient's condition. Hypertension with no identifiable cause is called essential or primary hypertension. It is also the most common type of hypertension. Secondary hypertension is hypertension resulting from an underlying condition, according to Audrey Howard, RHIA, of 3M Health Information Systems in Salt Lake City, UT.

Advice: When a patient has primary hypertension, you have to list that code first and then list any manifestations or secondary diagnoses. For secondary hypertension, you should report the underlying condition as the primary diagnosis and the hypertension as secondary.

Example: A patient has primary aldosteronism that is causing benign hypertension. Report 255.10 (Primary aldosteronism) as the primary diagnosis and 405.19 (Secondary hypertension; benign, other) as the secondary. Key: Physicians must learn to link the patient's hypertension to any other manifestations, and coders must learn to discern the manifestations properly to assign the correct codes, stresses Darling.

Don't Forget About Underlying Conditions

When you check the physician's documentation, don't be surprised if you see other conditions listed.

Keep in mind: Sometimes patients have hypertension with another condition, such as renal disease or renal artery stenosis, and there is one code that includes both conditions, explains Darling. For instance, the 403 code series indicates hypertensive renal disease, and the 404 series indicates hypertensive heart and renal disease.

Example #1: If your physician documents a patient with benign hypertensive renal disease with renal failure, you would report 403.11 (Hypertensive kidney disease; benign; with chronic kidney disease). You need only this one code to describe the patient's entire condition.

Example #2: If your physician treats a patients with benign hypertensive disease with heart failure, you would report 402.11 (Hypertensive disease; benign; with heart failure). This code indicates the patient's entire hypertensive status. Note: You would also need to report an additional code to specify the type of heart failure, such as 428.0 (Congestive heart failure, unspecified).

Red flag: If your physician documents the patient has heart disease due to hypertension, he should also indicate whether the disease is with or without heart failure, according to Darling. "This [distinction] will help the coder select the best code in the 402 or 404 categories," she adds. And if the patient does have heart failure, remember to assign a separate code to indicate the type of heart failure.

Note: See the chart on this page for a quick primer on which underlying conditions apply to primary and secondary hypertension.

Know Hypertension's Underlying Conditions And Sail To Coding Success

Use this handy chart to keep track of which underlying conditions coincide with primary and secondary hypertension--and ease your hypertension coding headaches.