Comparison of radiographic scoring methods in a cohort of RA patients treated with anti-TNF therapy

Abstract

To compare the ability of the simple erosion narrowing score (SENS) to classify radiographic progression relative to the Sharp/van der Heijde score (SHS) in a prospective cohort of anti-TNF-treated RA patients. Radiographs of the hands, wrists and feet of patients enrolled in a pharmacovigilance programme are performed every 2 years. These radiographs were read in chronological order by three rheumatologists and scored using the SHS. SENS scores were derived from the SHS. Additionally, one rheumatologist scored the radiographs using the SENS method only. Patients with radiographic progression in excess of the smallest detectable change were classified as progressors. The probability of agreement and κ-value between the SHS and SENS methods for determining progression was calculated. A sample of 25 patients was selected from the database. The annualized mean (s.d.) change in SHS score was 6.61 U (7.48 U) and in SENS score was 2.27 U (2.17 U). Five patients were classified as progressors using SHS and seven using SENS, with a probability of agreement of 84% (κ = 0.565). The SENS method captures radiographic progression reliably compared with the more detailed SHS method. SENS is suitable for application in clinical practice or in observational cohorts.