Comparing symptoms, treatment patterns, and quality of life of ankylosing spondylitis and non-radiographic axial spondyloarthritis patients in the USA: findings from a patient and rheumatologist Survey

OBJECTIVES: The aim of this study was to compare the symptoms, treatment patterns, and quality of life (QoL) of ankylosing spondylitis (AS) patients to non-radiographic axial spondyloarthritis (nr-axSpA) patients in the USA. METHOD: A cross-sectional survey was conducted with rheumatologists and their consulting patients in the USA from June through August 2018. Patients who had a rheumatologist confirmed diagnosis of AS and nr-axSpA were eligible to participate. Patient demographics, symptoms, and medication use were reported by the rheumatologist, while work disability and QoL measures were reported by the patient. Patient demographics, symptoms, QoL and treatment patterns of AS and nr-axSpA patients were compared using parametric tests and non-parametric tests when appropriate. RESULTS: A total of 515 AS patients and 495 nr-axSpA patients were included in this analysis. A higher proportion of AS patients were male (p < 0.001), older (p = 0.014), and more likely to be prescribed a biologic (p < 0.0001). On average, AS patients experienced slightly more symptoms at diagnosis (p = 0.023); however, nr-axSpA patients were more likely to experience enthesitis (p = 0.048) and synovitis (p = 0.003). Patient reported outcomes such as the ASAS Health Index (p = 0.171), ASQoL (p = 0.296), BASDAI (p = 0.124), and WPAI (p = 0.183) were similar between AS and nr-axSpA patients after adjusting for confounding variables such as medication use. CONCLUSIONS: AS and nr-axSpA patients share the same clinical features. The burden of the disease, as assessed by QoL measurements, is also similar in AS and nr-axSpA patients; however, despite these similarities, patients with nr-axSpA are less likely to be treated with a biologic. KEY POINTS: