Clinical assessment and outcome research in spondyloarthritis.

Spondyloarthritis (SpA; formerly called seronegative arthritis) generally follows a chronic course with an uncertain outcome and includes diseases, such as ankylosing spondylitis and psoriatic arthritis, that require regular medical care and monitoring to control for disease activity and maintain physical function. This article describes recent achievements in the field of clinical outcome assessment, imaging, and the classification of patients with SpA symptoms. Clinical instruments are addressed that measure function, disease activity, and pain through questionnaires, physical examination, and laboratory tests. Furthermore, the value of different imaging techniques for daily practice is described, and the new classification criteria for axial SpA are discussed.