Disease activity score (DAS) in rheumatoid arthritis

The disease activity score (DAS) is a scoring system developed in Europe for assessing the severity of rheumatoid arthritis

• calculated using a formula that includes counts for tender and swollen joints (53 and 44 joints respectively), an evaluation of general health by the patient (on a scale of 0 to 100), and a measure of circulating inflammatory markers

DAS28 is similar to DAS above but uses only 28 joints for assessment

• DAS28 score greater than 5.1 is considered to be indicative of high disease activity, between 5.1 and 3.2 of moderate disease activity and less than 3.2 of low disease activity
• a patient scoring less than 2.6 is defined as being in remission
• the European League Against Rheumatism (EULAR) response criteria are based on the DAS measure
  • a decrease in DAS28 score of 0.6 or less is considered to show a poor response, while decreases greater than 1.2 points indicate a moderate or good response, dependent on whether an individual's DAS28 score at the end point is above or below 3.2 respectively

Reference

1. NICE. Adalimumab, etanercept, infliximab, certolizumab pegol, golimumab, tocilizumab and abatacept for rheumatoid arthritis not previously treated with DMARDs or after conventional DMARDs only have failed. Technology appraisal guidance TA375. Published January 2016