Reappraisal of the diagnostic and prognostic value of morning stiffness in arthralgia and early arthritis: results from the Groningen EARC, Leiden EARC, ESPOIR, Leiden EAC and REACH

Jessica AB van Nies, Celina Alves, Audrey LS Radix-Bloemen, Cécile Gaujoux-Viala, Tom WJ Huizinga, Johanna MW Hazes, Elisabeth Brouwer, Bruno Fautrel, Annette HM van der Helm-van Mil

Morning stiffness is daily assessed in the diagnostic process of arthralgia and arthritis, but large-scale studies on the discriminative ability are absent. This study explored the diagnostic value of morning stiffness in 5,202 arthralgia and arthritis patients and the prognostic value in early Rheumatoid Arthritis (RA). In arthralgia patients referred to the Early Arthritis Recognition Clinics (EARC) of Leiden (n = 807) and Groningen (n = 481) or included in the Rotterdam Early Arthritis Cohort (REACH)-study (n = 353,) the associations (cross-sectional analyses) between morning stiffness and presence of arthritis at physical examination were studied. In early arthritis patients, included in the Leiden Early Arthritis Clinic (EAC) (n = 2748) and Evaluation et Suivi de POlyarthrites Indifférenciées Récentes (ESPOIR) (n = 813), associations with fulfilling the 2010-RA criteria after 1-year were assessed. In 2010-RA-patients included in the EAC (n = 1140) and ESPOIR (n = 677), association with the long-term outcomes Disease Modifying Anti-Rheumatic Drug (DMARD)-free sustained remission and radiological progression were determined. Morning stiffness was defined as a duration ≥60 minutes; sensitivity analyses were performed for other definitions. In arthralgia, morning stiffness (≥60 minutes) associated with the presence of arthritis; Leiden EARC odds ratio (OR) 1.49(95%CI1.001-2.20), Groningen EARC OR2.21 (1.33-3.69) and REACH OR1.55(0.97-2.47) but the area-under-the-curves (AUC) were low (0.52, 0.57, 0.54). In early arthritis, morning stiffness was associated with 2010-RA independent of other predictors (Leiden EAC OR1.72 (95%CI1.31-2.25, AUC0.68), ESPOIR OR1.68 (1.03-2.74, AUC0.64)). ≥30 minutes duration provided optimal discrimination for RA in early arthritis. Morning stiffness was not associated with radiological progression or DMARD-free sustained remission. Morning stiffness in arthralgia and early arthritis is associated with arthritis and RA respectively. This supports the incorporation of morning stiffness in the diagnostic process.