In patients with axial spondyloarthritis (axSpA), use of the Bath Ankylosing Spondylitis Metrology Index (BASMI) provides a moderately accurate estimate of disease activity, and is an independent predictor of response to biologic therapy for some commonly used measures, according to study results published in Arthritis Care & Research (Hoboken).
The researchers sought to establish the factors associated with reduced spinal mobility in patients with axSpA and to determine whether poor mobility was predictive of a response to antitumor necrosis factor (TNF) therapy.
A prospective UK cohort study was conducted among individuals who fulfilled the Assessment of Spondyloarthritis International Society (ASAS) criteria for axSpA. At study enrollment, patient-reported factors and clinical measures independently associated with spinal mobility, as measured by BASMI, were established. Among individuals initiating anti-TNF therapy, factors that were independent predictors of response to therapy were established using ASAS criteria, quality of life (QOL) measures, and Anklylosing Spondylitis Disease Activity Score (ASDAS) criteria.
A total of 1960 patients were eligible for study participation. The median patient age was 48 years (range, 37-59 years). Overall, 70% of the participants were men, and the median BASMI score was 3.6 (range, 2.2-5.3). The following factors were independently associated with poor spinal mobility: fulfilling radiographic criteria for ankylosing spondylitis; poorer function; higher levels of inflammation, based on C-reactive protein levels; longer duration of symptoms; the male sex; older age; lower level of education; and lack of current employment.
Poorer mobility, as reflected in a higher BASMI score, was an independent predictor of not fulfilling response criteria for ASAS 20% improvement (odds ratio [OR] per increasing score, 0.80 [IQR, 0.66-0.98]); ASAS 40% improvement (OR, 0.69 [IQR, 0.50-0.95]); and QOL, which was assessed using the Ankylosing Spondylitis Quality of Life Questionnaire (β=0.64 [IQR, 0.26-1.02), but was not associated with fulfilling ASDAS response criteria.
The researchers concluded that the role played by the BASMI score in disease monitoring and clinical decision-making in patients with axSpA, particularly in situations in which face-to-face consultations are likely to become less common, remains to be determined.
Biallas RL, Dean LE, Davidson L, et al. Role of metrology in axial spondyloarthritis: does it provide unique information in assessing patients and predicting outcome? Results from the British Society for Rheumatology Biologic Register for Ankylosing Spondylitis. Arthritis Care Res (Hoboken). Published online 2022. doi:10.1002/acr.24500