Clinical performance of the ASAS health index in chinese patients with ankylosing spondylitis and its influencing factors.

Objective: The aim of this study was to investigate the status of health-related quality of life in Chinese patients with ankylosing spondylitis (AS) and to analyze factors associated with the Assessment of SpondyloArthritis international Society Health Index (ASAS-HI) in AS and its relationship with disease activity and psychological status.

Methods: A cross-sectional study of 484 patients with AS attending 10 hospitals in China from March 2021 to September 2023 was recruited. The ASAS-HI assessed general health and functional status; the Depression Anxiety Stress Scales (DASS-21) assessed psychological disorders such as anxiety, depression, and stress; and the Functional Assessment of Chronic illness Therapy-Fatigue Scale (FACIT-F) assessed patients' fatigue symptoms; the Ankylosing Spondylitis Disease Activity Score-C-Reactive Protein (ASDAS-CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), and Bath Ankylosing Spondylitis Measurement Index (BASMI) were used to assess patients' disease activity and functional impairment. The correlation between ASAS-HI and the ASDAS, poor psychological status, and fatigue symptoms was observed. Univariate and multivariate logistic regression analyses were used to explore the relevant influencing factors of ASAS-HI.

Results: A total of 484 patients were included in this study of whom 162 were in poor health, 139 in moderate health, and 183 in good health. On univariate analysis, disease activity is an important factor affecting ASAS-HI. People with extremely high disease activity (ASDAS ≥ 3.5) had a 12 times elevated risk of having poor health status (OR = 12.53; P < 0.001). Other significant covariates included age ≥ 36 (OR = 1.58; P = 0.015), BMI ≥ 24 kg/m (OR = 2.93; P = 0.013), smoke (OR = 1.96; P = 0.002), BASFI (OR = 1.49; P < 0.001), BASMI (OR = 1.22; P < 0.001), fatigue (OR = 6.28; P < 0.001), and bad psychological conditions such as depression (OR = 10.86; P < 0.001), anxiety (OR = 3.88; P < 0.001), and stress (OR = 4.65; P < 0.001). The use of bMARDs is inversely associated with the appearance of adverse health status (OR = 0.54; P = 0.012). There was no significant relationship between HLA-B27 and sex. Multivariable logistic regression showed that higher disease activity (ASDAS ≥ 3.5) (OR = 5.14; P = 0.005), higher scores of BASMI (OR = 1.10; P = 0.009), self-reported depression (OR = 3.68; P = 0.007), and fatigue (OR = 2.76; P < 0.001) were factors associated with adverse health status.

Conclusion: The health status of AS patients is related to age, BMI, smoking, disease activity, poor psychological status, and fatigue and is influenced by a combination of multiple factors such as emotional state, economic level, pain, and dysfunction. Therefore, clinicians should pay attention to the early assessment of ASAS-HI in order to improve the prognosis of the disease. Key Points •Ankylosing spondylitis (AS) is a chronic inflammatory autoimmune disease with a long course and heavy disease burden, which greatly affects patients' quality of life. Therefore, this study aims to evaluate the health status of ankylosing spondylitis in the Chinese population and its influencing factors. •This is a multi-center cross-sectional study in China, which can better reflect the overall situation of the Chinese population.