Objective: To create a core set of measurement concepts for use in the creation and maintenance of anti-tumor necrosis factor-alpha patient registries in ankylosing spondylitis (AS).
Methods: A Delphi-based approach was used to identify elements that best identify a patient's clinical state, disease progression, and potential drug-related toxicities. Decision-making was based on systematic literature reviews and clinical experience and expertise.
Results: A core set of measurement domains was defined including disease activity and physical function outcomes. Comparison with domains used in existing AS registries showed excellent agreement with current practice.
Conclusion: This core set is a basis for data collection across AS populations.