An introduction to measurements in rheumatology by Dr. Chandrashekara. S. It is important to measure the disease activity to evaluate the clinical and therapeutic approaches to rheumatic disease. Measurement of disease activity score (DAS) is a clinical guide path in rheumatic disease that helps to maintain disease control, alter the therapy according to the state of the disease and improve quality of life (QOL) and life expectancy. Watch this video to learn more about the measurements and their importance in rheumatology.