The New RA Criteria: An Interview with Dr. Gillian Hawker
One of the many exciting recent developments in the field of rheumatology was last year's development of new criteria. There's been much discussion of these criteria here on MyRACentral so to learn more, I interviewed Dr. Gillian Hawker, who was part of the working group that created the criteria.
The first thing I learned is that we had all misunderstood what these criteria are about. The media - even medical media - had been describing the new criteria as diagnostic, stating that they would make it easier to identify rheumatoid arthritis in its early stages. Although the identification part of that statement is true, the criteria are not diagnostic. They are classifying criteria, intended for use in clinical trials testing new medications for RA.
The previous classifying criteria used to define RA were created in 1987. According to Dr. Hawker, they "have a significant limitation as they were derived by trying to distinguish patients with established RA from those with a combination of other definite rheumatological diagnoses. They are therefore not helpful in achieving the goal of identifying patients who would benefit from early effective intervention."
The Biologic medications (Enbrel, Humira, Orencia, etc.) are the driving force behind this change. It is because of the revolutionary impact of these types of drugs that the goal of treatment is now "to prevent individuals from reaching the chronic, erosive disease state that exemplifies the 1987 criteria for RA," Dr. Hawker says. This is a significant change from the past treatment goal of merely slowing the progression of RA.
The efficacy of early intervention has to be demonstrated scientifically and it was therefore necessary to "develop new classification criteria for RA to facilitate the study of persons at earlier stages of RA," Dr. Hawker says. The working group consisted of members from The American College of Rheumatology and the European League against Rheumatism. Dr. Hawker says that the goal of the project was to "develop a set of rules to be applied to newly presenting patients with undifferentiated synovitis that would: identify the subset at high risk for persistent inflammation leading to joint damage; be used as a basis for initiating disease modifying therapy; and that would not exclude classification of patients later in the disease course."
The project had three phases. Dr. Hawker explained that in Phase 1, data from a selection of international patients was used to identify "patient factors, e.g., number and distribution of joints affected, serology and duration of symptoms, and their relative weights (i.e. the comparative importance of these factors), that predicted the subsequent disease in a position to start MTX (i.e., methotrexate)" as this would indicate individual doctor's "opinion that the patient what is risk for developing persistent and/or erosive arthritis that we were currently considered to be 'RA'." In the second phase, expert RA clinicians worked to "reach consensus on factors important in determining the probability of developing RA. Decision analytic software was employed to describe the relative weights for each of the factors," Dr. Hawker said. In the last phase of the project, she explained the results of Phases 1 and 2 were used to "develop a scoring system that would be applicable to newly presenting patients with undifferentiated inflammatory arthritis to permit the identification of those with high probability of developing persistent and/or erosive RA." This scoring system was designed to include a differentiation of "probable" and "definite" RA based on the fact that people may "present for the first time at later stages of disease."
I asked Dr. Hawker of the differences between the old and new criteria and although it turned out to be like asking someone to compare apples and oranges, she mentioned four primary differences
1. "The new criteria do not incorporate x-ray damage (erosions) or nodules, or other late stage RA changes, as the intent is to identify and treat people early so as to prevent easily changes";
2. the new criteria do not include how long a person has experienced joint stiffness or symmetry of joint involvement as neither have been identified by "current evidence as predictive of subsequent development of persistent or erosive RA";
3. the new criteria "incorporate new knowledge about the role of anti-citrullinated protein/peptide antibodies (ACPA) in predicting prognosis in RA";
4. "a greater number of subjects with early RA will meet the new criteria than the old criteria - this will enabling inclusion of such patients in future clinical trials of new therapeutics for RA."
Not surprisingly, some doctors are adapting these new criteria for use in a clinical setting as a diagnostic aid. Dr. Hawker emphasizes that "the focus of this endeavor was not on developing diagnostic criteria for RA. A separate body of work is required to develop such tools which may be informed by these new classification criteria." However, should clinicians be guided in their practice by the new criteria, it is important to emphasize that "all synovial joints that may be affected in RA other than those that are typically affected by osteoarthritis (this is the base of the thumb, big toe and the end joints of the fingers) should be considered in counting the number of 'involved joints' in the new criteria. Further, because physicians often have difficulty distinguishing swollen joint from one that is not swollen, the new criteria consider a joint as 'involved' or affected in the presence of tenderness OR swelling," Dr. Hawker states.
Dr. Hawker is optimistic about the impact of the new criteria on clinical trials, stating that the "reason for their development is to push our ability to study new therapies in RA early in the stage of the disease - that is, to see if we can actually prevent joint damage from occurring." As well, the advances in treatment of RA mean that "a separate task force has been working on the development of criteria for remission in RA."
On a personal note, I have had RA for over 40 years and the fact that not only has the therapeutic goal changed from slowing the progression of RA to preventing the kind of damage that are seen in all of my joints, but that we are now looking at criteria for determining remission is, to put it bluntly, blowing my mind. I never thought I would see such advances in my lifetime, but thanks to Dr. Hawker and others like her, we're now living in a whole new world.
Gillian A. Hawker, MD, MSc, is Professor of Medicine and Rheumatology in the Departments of Medicine and Health Policy, Management and Evaluation at the University of Toronto. She is a clinical epidemiologist and health services researcher who has focused her research on study of the access to, and outcomes of, clinical care for osteoarthritis, OA, and qualitative and quantitative research on the determinants and consequences of pain in OA.
Lene Andersen is the author of the award-winning blog The Seated View.