Clinical Outcome Measures in RA

DAS28 in Obese Patients May Be Overestimated

In an obese rheumatoid arthritis (RA) patient, a clinically assessed swollen joint (SJ) diagnosis is…
mdedge.com

In obese patients, rheumatologists may mistake fat fingers for joint swellings.  This inadvertently results in a higher disease activity score (DAS), subjecting such patients to unnecessary and potentially hazardous treatment intensification.

In a shooting analogy, this constitutes a precision error.


Objective To investigate the predictive value of discordance between (1) tender and swollen joint count and (2) patient’s and evaluator’s global assessment on remission in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA). Methods From the prospective, multicentre Norwegian-Disea…
ard.bmj.com

In this study, joint tenderness (what the patient feels) exceeds joint swelling (what the doctor assesses). Patient global (the patient’s overall perception of how the disease is affecting his/her life) also exceeds Physician global (the doctor’s overall gauge of the disease’s impact on the patient).

The researchers found that, the wider the discordance between joint tenderness and joint swelling, as well as the greater the discrepancy between the patient and the physician global assessment scores, the less likely the patient will achieve clinical remission.

Since remission comes with more intensive treatment, which in turn is dependent on a worse disease activity assessment, it logically follows that the fault lies with the physicians underestimating the true disease activity, rather than the patients exaggerating their symptoms.

Both form part of the various clinical outcome measures (DAS, CDAI, SDAI) currently used in guiding therapy towards disease remission, but it is obvious that the patient’s input approximates true disease activity far better than the physician’s, and should therefore be given more weightage in the treat-to-remission-target strategy.  In fact, in the latest stringent EULAR Boolean remission criteria, the physician global has been dropped while retaining the patient global!

Again in a shooting analogy, the doctor’s understated contribution to the DAS constitutes an accuracy error.