Fig. 1

a Decision tree for the first year comparing the current diagnostic test strategy with the new diagnostic add-on test strategy for intermediate-risk patients. Current test strategy American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) 2010 rheumatoid arthritis (RA) classification criteria. New test strategy add-on test for intermediate-risk patients (3–5 points) according to the ACR/EULAR 2010 RA classification criteria. IA inflammatory arthritis, MTX methotrexate, TP true positive, FP false positive, TN true negative, FN false negative, T0 baseline, T6 6 months, T12 12 months. b Patient-level transition state model and background model of second to fifth year for all test strategies. DAS28 disease activity score in 28 joints