NEW YORK – Axial spondyloarthritis is not being seen by U.S. rheumatologists at a rate commensurate with prevalence, according to an expert providing the rationale for a major educational initiative.
In the United States, several studies, including the most recent, suggest that the prevalence of axSpA is at least as great as that of rheumatoid arthritis even though most rheumatologists see a much lower proportion of axSpA patients, according to Dr. Atul Deodhar, medical director of the rheumatology clinics at Oregon Health & Science University, Portland.
Dr. Atul Deodhar
The reasons for this disparity are not fully understood, but it has prompted a major educational initiative by the Spondyloarthritis Research & Treatment Network (SPARTAN), according to Dr. Deodhar, who spoke at the joint meetings of SPARTAN and the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis. The goal of the initiative is to reduce the delay to diagnosis and to funnel these patients more efficiently to experts in inflammatory joint diseases.
The most recent U.S. prevalence estimate for axSpA is 0.7%, reported Dr. Deodhar, citing a study that employed Assessment of Spondyloarthritis International Society (ASAS) criteria (Arthritis Care Res. 2013;65:1299-306). Other studies have generated prevalence rates as high as 1.4%, but even this lower recent estimate exceeds the typically cited 0.6% estimated prevalence rate for RA, he said.
"One wonders where these patients are going," said Dr. Deodhar, emphasizing the relative infrequency with which axSpA is managed by U.S. rheumatologists.
Some of these patients are likely to be seen by orthopedists, chiropractors, internists, or other health care providers, but one concern is that many are not being seen at all or at least not until the disease has advanced. Dr. Deodhar cited evidence that the average delay to diagnosis of axSpA in the United States is 6-8 years, which is likely to worsen outcome.
"Several studies suggest that partial remission is about double when patients are caught early and treated appropriately," Dr. Deodhar said. However, although rheumatologists are in the best position to help axSpA patients, they might be part of the problem, he said.
"Rheumatologists have traditionally shied away from seeing patients with back pain, because 95% of these patients have mechanical pain for which rheumatologists do not have much to offer," Dr. Deodhar said.
Yet for those with an inflammatory etiology, rheumatologists can play an essential role in treatment that slows or halts progression. A SPARTAN initiative has been specifically planned to educate those health care providers likely to hear initial complaints of lower back pain as well as to increase attention to axSpA by rheumatologists.
For referral physicians, the initiatives are being focused on increasing awareness of inflammatory back pain and providing simple criteria for referral, according to Dr. Deodhar. The ASAS diagnostic criteria for axSpA are considered sensitive and specific, but simplified referral strategies may accelerate the time to a specialist consultation.
Several referral strategies are effective. Dr. Deodhar cited one study that tested two. In one strategy, a referral was made in patients younger than 45, with chronic back pain of at least 3 months, who met two of three screening criteria: inflammatory back pain, HLA-B27 positivity, or sacroiliitis on imaging. In the other, the same criteria were employed and patients had to have a positive family history of ankylosing spondylitis or a good treatment response to NSAIDs (J. Rheumatol. 2011;38:2452-60).
With the first strategy, "nearly 42% [41.8%] had definite axSpA," according to Dr. Deodhar. The slightly lower sensitivity of the other was not inferior statistically, but the first strategy was preferred for simplicity.
These types of referral strategies will be included in the SPARTAN educational initiatives being developed to improve early recognition of axSpA and to bring patients to the specialists most suited to offering effective management.
Dr. Deodhar reported financial relationships with Amgen, Abbott, Genentech, and Janssen.