gms | German Medical Science

Introduction: Axial spondyloarthritis (axSpA) is often diagnosed late, while there is also a problem of over- and misdiagnosis in patients with chronic back pain. Imaging, especially magnetic resonance imaging (MRI), is important for diagnosis and differential diagnosis, but interpreting imaging findings in sacroiliac joints requires specific expertise. The Improve-axSpA project aimed to assess the effectiveness of telemedicine support in enhancing the diagnostic accuracy of patients suspected of having axSpA.

Methods: We established a central telemedicine platform that allowed the collection of clinical and imaging information from patients who presented to rheumatologists and orthopaedists with suspicion of axSpA and in who a definite diagnosis was considered problematic. The platform allowed for a central evaluation of the submitted information by rheumatologists with expertise in clinical assessment and imaging evaluation of axSpA (XB, DP). Participating centres were encouraged to recruit appropriate patients consecutively. Collected information included the suspected diagnosis and imaging findings, demographic and laboratory data, information on potential mechanical stress factors (physical activity, work, history of pregnancies and deliveries), characteristics of back pain and general SpA items as assessed by the local physician. The central evaluation included detailed evaluation of submitted data and the final conclusion on the presence, absence or inconclusive axSpA. The project is ongoing and here we report interim study results on the agreement between central and local assessment and potential factors associated with evaluation discrepancies.

Results: A total of 25 study centres submitted 277 cases for the central evaluation between August 2021 and March 2023. The distribution of the diagnoses according to the local and central assessment is presented in table 1 [Tab. 1]. A total of 90/277 patients (33%) were locally diagnosed with axSpA. Only in 45 (50%) of those cases axSpA could be confirmed after central evaluation, while in 32 patients (36%) an alternative reason of back pain (in the majority of cases – degenerative/mechanical disorders, non-specific back pain) were found to be more likely than axSpA according to the central experts. In contrast, among 82 patients with no axSpA according to local assessment, in 70 (85%) of those patients axSpA could be excluded based on central evaluation. In 105 cases with inconclusive local diagnosis, axSpA was more frequently excluded than confirmed (73% vs. 15%) according to central assessment. In a total of 30 patients, the diagnosis could not be finally determined after central assessment, this being related in most cases to insufficient imaging. Several important differences could be found between patients with centrally confirmed vs. excluded axSpA: patients without SpA were older, more often females (and more often with a history of pregnancies and 2 and more deliveries), had lower CRP, higher BMI and were less frequently HLA-B27-positive. At the same time, other SpA-characteristics including inflammatory back pain, as well as imaging characteristics as reported by the local rheumatologist were not discriminative between the groups. However, the presence or absence of SpA-compatible active inflammatory and structural changes on MRI of sacroiliac joints according to the central assessment were highly discriminative between the groups with confirmed and excluded SpA.

Conclusion: The Improve-axSpA interim analysis suggests a high risk of overdiagnosis of SpA in daily clinical practice. Telemedicine tools with central evaluation of clinical and imaging information may be helpful in the diagnostic process for patients with suspected axSpA.

Disclosure: Improve-axSpA project is supported by Novartis Pharma GmbH.

Potential conflict of interest: DP: Research support from: AbbVie, Eli Lilly, MSD, Novartis, Pfizer; Consulting fees from: AbbVie, Biocad, Eli Lilly, Galapagos, Gilead, GlaxoSmithKline, Janssen, MSD, Moonlake, Novartis, Pfizer, Samsung Bioepis, and UCB; Speaker fees from: AbbVie, Bristol-Myers Squibb, Eli Lilly, Janssen, MSD, Medscape, Novartis, Peervoice, Pfizer, and UCB.

MKä: none declared.

MKr: none declared.

BS: none declared.

CA: none declared.

AW: none declared.

IR: none declared.

XB: Research support from: AbbVie, MSD, Novartis, Consulting fees from: AbbVie, Eli Lilly, Galapagos, Gilead, GSK, Janssen, MSD, Moonlake, Novartis, Pfizer and UCB; Speaker fees from: AbbVie, Bristol-Myers Squibb, Eli Lilly, Janssen, MSD, Medscape, Novartis, Peervoice, Pfizer, and UCB.