Measuring RA Disease Activity

The more you and your doctor know about your RA, the better you can manage it. Your doctor will regularly monitor your disease activity, which is the term used to refer to ongoing inflammation, symptoms, and/or joint damage. This regular and systematic monitoring is critical to managing the condition.Information about the level of disease activity allows doctors to monitor your response to treatment and to adjust your treatment as needed.

One commonly used measure of disease activity is the DAS28 (Disease Activity Score with 28 joint counts). The DAS28 involves a count of tender and swollen joints, your own assessment of your health, and lab tests to identify inflammation. The lab tests measure the erythrocyte sedimentation rate (ESR) or levels of C-reactive protein (CRP). Other composite measures of RA disease activity are also available.

A newer way to measure disease activity is with the Vectra DA test, which is an innovative blood test that allows doctors to test for several biological markers (or biomarkers) of RA simultaneously. The test must be ordered by a physician. Vectra DA measures the levels of 12 proteins in the blood—biomarkers that have been linked to RA disease activity—and then combines them into a single score (between 1 and 100) that classifies your current level of RA disease activity as “low”, “moderate”, or “high”. The test does not replace a doctor’s evaluation, but it does provide a precise, objective measure of the underlying biology of your RA. Testing with Vectra DA can provide snapshots of your disease activity at specific points in time, which can help you and your doctor to better manage your RA.