Validation of Disease Activity Measurement Thresholds for Arthritis Treatment

Rheumatoid arthritis (RA) is a chronic (long-lasting) autoimmune disease that mostly affects joints. RA occurs when the immune system, which normally helps protect the body from infection and disease, attacks its own tissues. The disease causes pain, swelling, stiffness, and loss of function in joints. Doctors use lots of ways to decide whether the disease is "active" in order to inform whether to change therapies.
I have developed modified disease activity scores (an overall score that represents how "active" the disease is at a given time) that correlates better with inflammation and damage in the joints seen in studies. To date, these scores have no clear "cutoffs" to be used in clinical practice in order to say who has "low" or "high" disease activity.
The goal of the proposed study is to determine whether cutoffs defined for these modified disease activity scores are associated with a lower risk of joint damage over time, as shown in x-rays. The study will also compare these new cutoffs to the standard scores currently used.
This study is necessary because it will help to determine whether these new scores, which seem better in some ways, can be used to determine who has "low" or "high" disease activity and therefore influence how providers decide whether additional therapy is needed.
The study will use data from the requested trial and categorize individuals in the study according to whether or not they got to a "low" level of activity at 6 month. Then the study will evaluate whether those that reached a "low" level of activity were less likely to have joint damage over the course of follow-up. If little damage has occurred, it will help support the use of this "cutoff" for low disease activity for use in the real world.
The analysis methods will show how much change has happened in one group (those that are "low") compared to the other (those that stay "high"). This will be done with simple tests of comparison. The study will also look at the typical measures that are currently used in practice and see how the new approach compares to the old approach.