David Felson, MD, MPH: Assessing Disease Activity in Patients with RA and Low Joint Count

Rheumatology Network interviewed David Felson, MD, MPH, Professor of Medicine in Epidemiology at Boston University, to discuss his recent study, “Meaning of patient global assessment when joint counts are low in rheumatoid arthritis.”

Rheumatology Network: What initially sparked your team's interest in assessing whether disease activity reflected symptoms in patients with rheumatoid arthritis (RA)?

David Felson, MD, MPH: What sparked my interest was the exclusion of feet and ankles from our definition of remission in rheumatoid arthritis. We were defining people as being in remission, but we weren't examining their feet, ankles, or hips. We were trying to figure out if disease might still be present in those joints.

RN: What was the ultimate study design that your team utilized?

DF: Well, we looked at a cohort of patients who were followed who had long standing rheumatoid arthritis. They were asked about whether they were having pain in any of their joints and the particular joints were identified. They were also examined, but that examination, like many in rheumatoid arthritis, excluded the feet, ankles, and hips. So we could look at their self-reported pain in their feet, ankles, and hips, and see if those were still present when the rest of their joints looked like they were doing fine. We could also figure out, because they reported to us what their disease their overall disease activity was, we could identify those who reported not having disease that was under great control yet we knew what joints were bothering them.

RN: And what were the results of your study?

DF: The results showed that in patients with rheumatoid arthritis whose joint counts, without counting the feet, ankles, and hips, showed almost no disease, but whose disease was still active by patient self-report, that feet, ankle, and hip pain were pretty common. And that we might be missing persistent disease activity by not examining those joints.

RN: In your opinion, what is the clinical significance of these results?

DF: They tell us that when patients report that their disease is active, yet the limited scope joint count doesn't show anything, that rheumatologists and whoever is caring for those patients ought to be thinking about disease that's affecting joints that are counted (feet and ankles and hips). If those are affected by active rheumatoid arthritis, it might mean the patient needs even more treatment.

RN: Were there any strengths or limitations that you'd like to discuss?

DF: There's an important limitation in that we didn't examine the feet, ankles, or hips, so we don't know when patients report pain in those locations whether they actually have active rheumatoid arthritis in those locations.

RN:What are the next steps for your team? Do you plan on doing any further research on this topic?

DF: We're looking for an opportunity with patients who have all of those joints assessed, including the feet and ankles, to see if those really do account for persistent disease activity and that patients would therefore need to be more aggressively treated to control that disease.