THU0454 OA Pain Phenotypes Associated with Structural Progression and Change in Pain Over Time in Two Phase III Clinical Studies with Symptomatic Knee OA

BackgroundOsteoarthritis (OA) is recognized as a heterogeneous disorder, with several possible drivers of disease progression, including involvement of bone, cartilage and synovium. The degree of joint pain has been shown to be both diagnostic and prognostic for OA, but meaningful clinical characteristics to identify the group of patients at risk of rapid progression are still needed.ObjectivesThe aim of this analysis was to identify key pain characteristics (WOMAC 5 pain questions) associated with risk of structural progression, and notable changes in reported pain over time.MethodsA combined post-hoc analysis of two phase III RCTs (NCT00486434 and NCT00704847), evaluating the efficacy and safety of oral salmon calcitonin in patients with painful knee OA (N=2,206) was performed. Analysis of structural progression was made based on data from the placebo group only, stratifying patients into quintiles of baseline (BL)-reported WOMAC pain level and further investigating the 5 WOMAC pain subscale questions: Q1; during walking on a flat surface, Q2; using stairs (up or down), Q3 at night while in bed, Q4; sitting or lying and Q5; while standing. The association between joint space narrowing (JSN) and WOMAC pain was assessed in a mixed model with JSN as dependent variable and other relevant BL variables as fixed effects.ResultsSpearman correlation coefficients indicates that each WOMAC pain sub-score expresses individually different information, as rho coefficients ranged from a minimum of 0.40 between Q2 and Q3, and maximally 0.67 for Q3 and Q4 (p