The following is a summary of the “Sensitivity to Change of the ASAS Health Index in an Observational Real-Life Cohort Study,” published in the February 2023 issue of Rheumatology by Regierer, et al.

Patients with axial spondyloarthritis (axSpA) can be evaluated regarding their physical, mental, and social well-being using the ASAS Health Index (ASAS HI). The primary purpose of this research was to examine how sensitive ASAS HI is to change about well-established variables of disease activity, function, and mental health. Patients with axSpA from the RABBIT-SpA disease registry who had at least 12 months of follow-up data and completed ASAS HI questionnaires were considered. 

Patients filled out surveys measuring disease activity (Bath Ankylosing Spondylitis Disease Activity Index [BASDAI], Ankylosing Spondylitis Disease Activity Score [ASDAS]), physical functioning (Bath Ankylosing Spondylitis Functional Index [BASFI]), emotional health (5-item World Health Organization Well-Being Index [WHO-5]), and global functioning (ASAS HI). To evaluate how sensitively various variables responded to change, standard response means (SRMs) were computed. A total of 667 patients were included; 552 were given bDMARDs (552 patients), and 115 were given conventional synthetic DMARDs and/or nonsteroidal anti-inflammatory drugs (115 patients) (control group). The mean ASAS HI dropped from 6.9 at baseline to 5.1 at month 12 for those receiving bDMARDs and 5.9 to 5.6 for those receiving conventional treatment. The ASAS HI SRM in the bDMARD group was 0.52, while the SRMs for BASFI (0.59), WHO-5 (0.65), BASDAI (0.73), and ASDAS (0.90) were all lower. 

Pain (78% agreed), body position maintenance (75%), and energy/drive (73%) were the most commonly impacted ASAS HI domains. Overall, bDMARD-treated patients showed marked improvement across the board. The most significant reduction in pain was observed in the placebo group. Although changes in physical function (BASFI), mental health (WHO-5), and the overarching concept of functioning and health (ASAS HI) were moderate, disease activity scores (ASDAS, BASDAI) showed high sensitivity to change.

Source: jrheum.org/content/50/2/185