ROC curves on morning stiffness in early arthritis patients of the EAC (A) and ESPOIR (B). The AUCs were 0.68 in the EAC and 0.64 in ESPOIR. In the EAC, the optimal cutoff point (crossing of dashed lines) reflected a sensitivity of 77% and a specificity of 52%; morning stiffness duration at this point was 27.5 minutes. When selecting the point with 80% specificity, the sensitivity was 40% and the morning stiffness duration 67.5 minutes (EAC) and a sensitivity of 33% and a morning stiffness duration 62.5 minutes (ESPOIR). AUC, area under the receiver operating characteristic curve; EAC, Early Arthritis Clinic; ESPOIR, Evaluation et Suivi de POlyarthrites Indifférenciées Récentes.