To evaluate a stratified screening process for early identification of axial spondyloarthritis (axSpA) considering: 1) wait times from primary care to rheumatology screen; 2) incremental precision and accuracy from primary care to rheumatology screen; and 3) diagnostic delay.
Adults with low back pain (LBP) attending primary care LBP clinics prospectively underwent a primary standardized clinical screen. Patients with LBP >3 months and onset age <50 years were referred for a comprehensive secondary screen by a physiotherapist with advanced rheumatology training. At secondary screening, patients with inflammatory features were deemed to have a low, medium, or high risk of axSpA vs. no risk. Precision and accuracy of this screening strata were measured against a rheumatologist with axSpA expertise.
In all, 405 patients underwent primary and secondary screening. Mean age was 36.9 years (±9.9); 55% were female. HLA-B27 was present in 14.4%. Median wait time from primary to secondary screen was 15 days. AxSpA risk assignment by rheumatologist was: 64.9% (none or low risk axSpA) and 35.1% (medium or high risk axSpA). The best combination of sensitivity (68%), specificity (90%), positive (80%) and negative (84%) predictive values was evident with the secondary screen. 15.6% of patients received a final diagnosis of axSpA. Median LBP duration from onset to diagnosis was: 2 years (non-radiographic axSpA) and 7 years (ankylosing spondylitis).
A stratified interprofessional screening process can facilitate rapid diagnosis of persistent LBP, with high precision and accuracy, in patients with axSpA.