Since PsA is a very complex disease, a different tool is needed to measure disease activity. The ACR20, which measures a 20% improvement in symptoms, may also be used, but it’s not used as often because new products need to meet a higher bar to earn FDA approval. They measure a 50% improvement and 70% improvement in RA symptoms, respectively, before starting treatment and after being on a treatment medication for a specific period of time. The ACR50 and ACR70 are the most commonly used ACR tests.

Today, these scores are used in clinical trials and in the Food and Drug Administration (FDA) approval process as a way to record how effective a medication is at reducing symptoms.

The test was created to help standardize the assessment and evaluation of the effectiveness of treatment. ACR scores are a way for doctors to measure the improvement people with RA have after taking medication.