Advancing Early Identification of Axial Spondyloarthritis: An Interobserver Comparison of Extended Role Practitioners and Rheumatologists

Objective. To compare clinical impression and confidence of extended role practitioners (ERP) with those of rheumatologists experienced in axial spondyloarthritis (axSpA) according to (1) evaluation of patients with chronic back pain assessed for axSpA; and (2) magnetic resonance imaging (MRI) recommendation for further investigation of these patients.

Methods. Patients with ≥ 3 months of back pain and age of onset < 45 years were referred for axSpA evaluation. An ERP assessed consecutive patients and recorded standardized clinical information in written form. Three rheumatologists subsequently evaluated each patient based on the recorded information. Patients were classified as having axSpA or mechanical back pain based on clinical and investigative findings. Level of confidence was noted for classification and MRI indication. Agreement between assessors was evaluated using percentage agreement and κ coefficient.

Results. Fifty-seven patients were assessed. Interobserver agreement of clinical impression for all raters was moderate (κ = 0.52). Agreement of clinical impression between ERP and rheumatologists ranged between 71.2% (κ = 0.41) and 79.7% (κ = 0.57). Agreement of clinical impression among rheumatologists ranged from 74.1% (κ = 0.49) to 79.7% (κ = 0.58). All rater agreement for MRI indication was fair (κ = 0.37). ERP agreement with rheumatologist for MRI recommendation ranged from 64.2% (κ = 0.32) to 75% (κ = 0.48). Agreement for MRI indication among rheumatologists ranged from 62.9% (κ = 0.27) to 74% (κ = 0.47). Confidence in clinical impression was similar among all practitioners.

Conclusion. ERP with specialty training in inflammatory arthritis demonstrate clinical impressions comparable with those of rheumatologists in the assessment of axSpA. Incorporation of such roles into existing models of care may assist in early detection of axSpA.