Conference Coverage

Researchers make headway in understanding axSpA diagnostic delay


 

AT SPARTAN 2023

– With early diagnosis an ongoing complex target for axial spondyloarthritis (axSpA), new research may help to answer where the biggest delays lie.

Gregory McDermott, MD, a research fellow at Brigham and Women’s Hospital in Boston, led a pilot study with data from Mass General Brigham electronic health records. He shared top results at the annual meeting of the Spondyloarthritis Research and Treatment Network (SPARTAN) , where addressing delay in diagnosis was a major theme.

Included in the cohort were 554 patients who had three ICD-9 or ICD-10 codes and an imaging report of sacroiliitis, ankylosis, or syndesmophytes, and were screened via manual chart review for modified New York and Assessment of Spondyloarthritis International Society criteria.

The average diagnostic delay for axSpA was 6.8 years in this study (median, 3.8 years), relatively consistent with findings in previous studies globally, and the average age of onset was 29.5.

The researchers also factored in history of specialty care for back pain (orthopedics, physical medicine and rehabilitation, pain medicine) or extra-articular manifestations (ophthalmology, dermatology, gastroenterology) before axSpA diagnosis. Other factors included smoking and insurance status, along with age, sex, race, and other demographic data.

The results showed shorter delays in diagnosing axSpA were associated with older age at symptom onset and peripheral arthritis, whereas longer delays (more than 4 years) were associated with a history of uveitis, ankylosing spondylitis at diagnosis, and being among those in the 80-99th percentile on the social vulnerability index (SVI). The SVI includes U.S. census data on factors including housing type, household composition and disability status, employment status, minority status, non-English speaking, educational attainment, transportation, and mean income level.

Notable uveitis finding

Dr. McDermott said the team was surprised by the association between having had uveitis and delayed axSpA diagnosis.

Among patients with uveitis, 12% had a short delay from symptom onset to axSpA diagnosis of 0-1 years, but more than twice that percentage (27%) had a delay of more than 4 years (P < .001).

“We thought the finding related to uveitis was interesting and potentially clinically meaningful as 27% of axSpA patients in our cohort with more than 4 years of diagnostic delay sought ophthalmology care prior to their diagnosis, [compared with 13% of patients with a diagnosis within 1 year],” Dr. McDermott said. “This practice setting in particular may be a place where we can intervene with simple screening or increased education in order to get people appropriately referred to rheumatology care.”

Longer delays can lead to more functional impairment, radiographic progression, and work disability, as well as poorer quality of life, increased depression, and higher unemployment and health care costs, Dr. McDermott said.

Patients may miss key treatment window

Maureen Dubreuil, MD, MSc, assistant professor at Boston University and a rheumatologist with the VA Boston Healthcare System, who was not part of the study, said: “This study addressed a critically important problem in the field – that diagnosis of axSpA is delayed by 7 years, which is much longer than the average time to diagnosis for other forms of arthritis, such as rheumatoid arthritis, which is under 6 months.

“It is critical that diagnostic delay is reduced in axSpA because undiagnosed individuals may miss an important window of opportunity to receive treatment that prevents permanent structural damage and functional declines. This work, if confirmed in other data, would allow development of interventions to improve timely evaluation of individuals with chronic back pain who may have axSpA, particularly among those with within lower socioeconomic strata, and those who are older or have uveitis.”

Study tests screening tool

Among the ideas proposed for reducing the delay was a referral strategy with a screening tool.

Swetha Alexander, MD, a rheumatology fellow at the University of Utah, Salt Lake City, who presented her team’s poster, noted that, in the United States, patients with chronic back pain often come first to a primary care doctor or another specialty and not to a rheumatologist.

As an internal medicine resident at Yale University, New Haven, Conn., Dr. Alexander and colleagues there conducted the Finding Axial Spondyloarthritis (FaxSpA) study to test whether patient self-referral or referral by other physicians, guided by answers to a screening tool, could help to speed the process of getting patients more likely to have axSpA to a rheumatologist.

Dr. Alexander said they found that using the screening tool was better than having no referral strategy, explaining that screening helped diagnose about 34% of the study population with axSpA, whereas if a patient came in with chronic back pain to a primary care physician without any screening and ultimately to a rheumatologist, “you’re only capturing about 20%,” she said, citing estimates in the literature.

Questions may need rewording

However, the researchers found that patient interpretation of the screening questions was different depending on whether they were answering online or directly from a rheumatologist’s in-person questions. For more success, Dr. Alexander said, the questions may need to be reworded or more education may be needed for both patients and physicians to get more valid information.

For instance, she said, when the screening tool asks about inflammation, the patient may assume the physician is asking about pain and answer one way, but when a rheumatologist asks the question a slightly different way in the clinic, the patient may give a different answer.

First questions in portal, on social media

In the screening intervention (called A-tool) patients first answered three questions via the MyChart portal or Facebook. If they answered all three questions positively, they would move on to another round of questions and the answers would decide whether they would be eligible to come into the rheumatologist to get evaluated for axSpA.

At the study visit, rheumatologists asked the same questions as the online A-tool, which focus on SpA features with reasonable sensitivity and specificity for axSpA (no labs or imaging included). Clinicians’ judgment was considered the gold standard for diagnosis of axSpA.

The authors reported that 1,274 patients answered questions with the screening tool via Facebook (50%) and MyChart (50%) from April 2019 to February 2022. Among the responders, 507 (40%) were eligible for a rheumatologist visit.

As of May 2022, 100 patients were enrolled. Of the enrolled patients, 86 patients completed all the study procedures, including study visit, labs, and imaging (x-ray and MRI of the pelvis). Of the 86 patients, 29 (34%) were diagnosed with axSpA.

The tool appears to help narrow the chronic back pain patients who need to be seen by a rheumatologist for potential axSpA, Dr. Alexander said, which may help to speed diagnosis and also save time and resources.

Dr. McDermott, Dr. Dubreuil, and Dr. Alexander reported no relevant financial relationships. The FaxSpA study was supported with funding from Novartis and the Spondylitis Association of America.

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