ACR score is a scale to measure change in rheumatoid arthritis symptoms. It is named after the American College of Rheumatology. The ACR score is more often used in clinical trials than in doctor patient-relationships, as it allows a common standard between researchers. Different degrees of improvement are referred to as ACR20, ACR50, ACR70. ACR20 was initially proposed with ACR scoring, measuring a 20% improvement on a scale of 28 intervals. ACR50 and ACR70 were later proposed, corresponding to 50% and 70% improvements. The (RASS) is based on sections of the ACR scoring system.