Functional Measurement of Rheumatoid Arthritis

It’s not only “Where does it hurt,” but also “What are you able to do!"

There are many ways to measure RA. Of course you’ve heard the pincushion jokes. But, blood work is the simplest way to get a picture of what Rheumatoid Arthritis is doing in a body. Sometimes x-rays or other scanning devices can detect damage.

Actual disability is more difficult to appraise, though. Certain symptoms such as pain, stiffness, and weakness are tough to measure. However, they are important indicators of disease severity and progression.

Some doctors might ask patients, “Were does it hurt?” or “How bad does the pain on a 1 to 10 scale?” But, there is another question which is just as important. It is, “What can you do?”

Over the years, doctors have developed several instruments to gauge the disability that Rheumatoid Arthritis causes. They include the Health Assessment Questionnaire (HAQ), the Keitel function test (KFT), and the Arthritis Impact Measurement Scale (AIMS). They attempt to record limitations in joint motion and difficulty performing certain tasks.

The goal is to have a more objective way to measure, record, and predict ability to perform the daily tasks of life. That is sometimes referred to as “Global functional status.” See image; click on it to enlarge it.

Patients are classified according to their ability to perform activities related to these categories: self-care (bathing, dressing, grooming); vocational (job-related tasks); avocational (pleasure or hobby- related tasks). There are four labels based upon which types of tasks a patient can perform.

Measuring functional capacity at the time of diagnosis of Rheumatoid Arthritis is important. It is a strong predictor for functional status later in the disease progression. The severity of the Rheumatoid Arthritis (as judged by functional status) is an even more accurate predictor of future disability than is the duration of the RA.

Believe it or not, poor functional status is even useful for predicting (long term) mortality in Rheumatoid Arthritis. I don’t point that out to scare you, but only to explain why researchers confirm how critical functional status assessment is to your treatment. It is vital to discuss your functional status with your doctors. It is an essential part of your care.

What should we do? We should carefully fill out any forms which our doctors provide which ask for details about what kinds of tasks we can do and how difficult it is to perform them. We can also compare that to what we were able to do in the past (for example, one year ago or before we changed medications, etc). We can even provide our doctors with 2 short lists:

1) Tasks which we can currently accomplish, indicating level of difficulty, or amount of medication required to do them;

2) Tasks which we can no longer perform.

On a less serious note, this reminds me so much of those kindergarten report cards for little tasks: She needs help to tie her shoes; she feeds herself neatly; handwriting is barely legible; cleans up well, but needs encouragement. Let’s hope ours also says: shares and plays well with others.

NIH citation Rheumatology journal abstract