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 (September 2007). Adalimumab, etanercept and infliximab for the treatment of rheumatoid arthritis.