Measurement properties of radiographic outcome measures in Psoriatic Arthritis: A systematic review from the GRAPPA-OMERACT initiative

Background: Structural damage is as an important outcome in the Psoriatic Arthritis (PsA) Core Domain Set and its assessment is recommended at least once in the development of a new drug. Objectives: To conduct a systematic review (SR) to identify studies addressing the measurement properties of radiographic outcome instruments for structural damage in PsA and appraise the evidence through the Outcome Measures in Rheumatology (OMERACT) Filter 2.1 Framework Instrument Selection Algorithm (OFISA). Methods: A SR was conducted using search strategies in EMBASE and MEDLINE to identify full-text English studies which aimed to develop or assess the measurement properties of radiographic outcome instruments in PsA. Determination of eligibility and data extraction was performed independently by two reviewers with input from a third to achieve consensus. Two reviewers assessed the methodology and results of eligible studies and synthesized the evidence using OMERACT methodology. Results: Twelve articles evaluating radiographic instruments were included. The articles assessed nine peripheral (hands, wrists and/or feet) and six axial (spinal and/or sacroiliac joints) radiographic instruments. The peripheral radiographic instruments with some evidence for reliability, cross-sectional construct validity and longitudinal construct validity were the Ratingen and modified Sharp van der Heijde scores. No instruments had evidence for clinical trial discrimination or thresholds of meaning. There was limited evidence for the measurement properties of all identified axial instruments. Conclusion: There are significant knowledge gaps in the responsiveness of peripheral radiographic instruments. Axial radiographic instruments require further validation, and the need to generate novel instruments and utilise other imaging modalities should be considered. (c) 2021 Elsevier Inc. All rights reserved.

Automated summary

This systematic review focused on the measurement properties of radiographic outcome instruments for structural damage in Psoriatic Arthritis, identifying significant knowledge gaps in the responsiveness of peripheral radiographic instruments and the need for further validation of axial instruments. The peripheral instruments Ratingen and modified Sharp van der Heijde scores showed some evidence of reliability and validity while the evidence for axial instruments was limited.