Radiology Coding Alert

Apply these measures to boost your rheumatoid arthritis coding ability.

You've got to be particularly careful when coding patients with a rheumatoid arthritis diagnosis. That's because it's one of the most comprehensive portions of the ICD-10 index.

And if you're not familiar with each variance of the diagnosis, you could quickly find yourself in over your head.

Read further for all you need to know to confidently code any rheumatoid arthritis diagnosis.

Rely on Index to Determine Subtype

More often than not, a provider will refer a patient for imaging without further specifying beyond rheumatoid arthritis, in which case you would opt for the unspecified code M06.9 (Rheumatoid arthritis, unspecified). However, you should consider these three different types of rheumatoid arthritis, which can then be further broken down by specificity:

• M08.-, Juvenile rheumatoid arthritis

            o M08.2-, Juvenile rheumatoid arthritis with systemic onset
            o M08.3-, Juvenile rheumatoid polyarthritis (seronegative)
            o M08.4-, Pauciarticular juvenile rheumatoid arthritis
            o M08.8-, Other juvenile arthritis

• M06.-, Other rheumatoid arthritis

            o M06.8-, Other specified rheumatoid arthritis
            o M06.0-, Rheumatoid arthritis without rheumatoid factor (seronegative)

• M05.-, Rheumatoid arthritis with rheumatoid factor (seropositive)

            o M05.8-, Other rheumatoid arthritis with rheumatoid factor
            o M05.7-, Rheumatoid arthritis with rheumatoid factor without organ or systems involvement.

Know Difference Between Seropositive, Seronegative RA

In order to excel at coding rheumatoid arthritis diagnoses, you've got to have a fundamental understanding of the difference between a diagnosis of seropositive and seronegative rheumatoid arthritis. Simply put, a physician may diagnose a patient with seropositive rheumatoid arthritis when their blood test indicates the presence of antibodies that can cause symptoms of rheumatoid arthritis.

On the other hand, seronegative rheumatoid arthritis is just the opposite - a diagnosis of rheumatoid arthritis without the presence of certain antibodies in the blood. When a patient tests negative for these antibodies, yet still shows strong symptoms of rheumatoid arthritis, thepatient may be diagnosed with seronegative rheumatoid arthritis.

If a patient's indicating diagnosis does not specify seronegative, seropositive, or with/without rheumatoid factor, you are not to make any assumptions in respect to the patient's rheumatoid arthritis diagnosis. Instead, you should opt for the unspecified code M06.9.

Be Wary when Coding Rheumatoid Bursitis

Be careful when coding certain conditions along with rheumatoid arthritis. As all coders are acutely aware, no assumptions should be made in the process of determining the correct diagnosis code. This is especially true in the cases of coding bursitis and nodules on patients with a diagnosis of rheumatoid arthritis.

Example: Rheumatoid arthritis without rheumatoid factor and bursitis of the right hand.

Sometimes, knowing too much as a coder can hurt you. In this case, assuming you're well versed in rheumatoid arthritis coding, you would know that the diagnosis code M06.241 (Rheumatoid bursitis, right hand) is a possibility right off the bat. You will see that no diagnosis code for rheumatoid arthritis with rheumatoid bursitis of the hand exists, taking that option off the table. The last option is to code as M06.041 (Rheumatoid arthritis without rheumatoid factor, right hand) and M70.11 (Bursitis, right hand).

"While rheumatoid arthritis can result in rheumatoid bursitis, coders should not make the assumption that one is the result of the other," explains Lindsay Della Vella, COC, medical coding auditor at Precision Healthcare Management in Media, Pennsylvania. "Since the bursitis could be the result of another variable, such as injury, it would be incorrect for the coder to assume otherwise," Della Vella says.

The answer to this coding dilemma depends on the amount of information the coder has to work with. In this case, there isn't enough to lead us to code rheumatoid bursitis.

Remember: In the instance that the indication and/or impression documents bursitis of the hand as a result of rheumatoid arthritis, you would apply code M06.241 as the sole diagnosis. In most cases, if one diagnosis is a symptom of another, the general rule is to code the primary diagnosis. However, in this case, the rheumatoid bursitis diagnosis indicates that rheumatoid arthritis is the primary cause of the bursitis.

Apply Same Rules for Rheumatoid Nodules

Using the example above, it's much easier to come to a correct diagnosis code when dealing with an indication of rheumatoid arthritis without rheumatoid factor of the right hand in addition to a diagnosis of nodules. Using the same logic, you cannot make the determination that a diagnosis of M06.341 (Rheumatoid nodule, right hand) is applicable, since there is no evidence that the nodule is a result of the rheumatoid arthritis.

You might consider coding this example as M06.041 and R22.31 (Localized swelling, mass and lump, right upper limb). Since a diagnosis of nodule of the right hand cannot be found within the index, your only option is to code as a localized mass. However, if the physician documents to nodule within a particular joint, the coding would be entirely different. While the index will still not lead you to any conclusive answer, you will have to resort to coding this diagnosis as M25.9 (Joint disorder, unspecified).

Side note: On the subject of arthritis coding, you will want to be aware of the upcoming ICD-10 change when coding osteoarthritis of the knee. You will now code osteoarthritis of the knee that the physician does not document as primary or secondary as primary osteoarthritis, by default. Code M17.9 (Osteoarthritis of knee, unspecified) will no longer be applicable and you will substitute it with code M17.1- (Unilateral primary osteoarthritis of knee...).