Median erosion scores in patients with Clinically Suspect Arthralgia with triple stratification for anti-citrullinated protein antibodies (ACPA), rheumatoid factor (RF) and local joint inflammation. Median erosion scores are shown with the upper limit of the interquartile range (75th percentile): *p < 0.01 compared to the ACPA−RF− magnetic resonance imaging (MRI)−group; **p < 0.01 as compared to the ACPA–RF–MRI– group; NS, non-significant as compared to the ACPA–RF–MRI– group. The following comparisons were made: ACPA−RF−MRI− patients (median erosion score 1.0) vs. ACPA+RF−MRI− (median 1.0; p = 0.85), ACPA−RF−MRI− vs. ACPA−RF + MRI− (median 0.5; p = 0.35) and ACPA−RF−MRI− vs. ACPA+RF + MRI− (median 1.0; p = 0.65). ACPA+RF + MRI− patients (median 1.0) vs ACPA−RF + MRI− patients (median 0.5; p = 0.91). Next, ACPA−RF−MRI− patients were compared to ACPA+RF−MRI+ (median 2.0; p = 0.033) and ACPA−RF + MRI+ patients (median 2.25; p = 0.001). Finally, ACPA+RF + MRI+ patients were compared to ACPA−RF−MRI− patients (median 2.5 versus 1.0; p < 0.0001) and ACPA+RF + MRI− patients (median 2.5 versus 1.0; p = 0.039). The number of patients in each group was as follows: ACPA−RF−MRI− (n = 214), ACPA+RF−MRI− (n = 4), ACPA−RF + MRI− (n = 26), ACPA−RF−MRI+ (n = 174), ACPA+RF + MRI−(n = 8), ACPA−RF + MRI+ (n = 24), ACPA+RF−MRI+ (n = 11) and ACPA+RF + MRI+ (n = 46)