Health Impairment in Spondyloarthritis Associated With High Disease Activity, Worsening Functionality, and Concomitant Fibromyalgia

Man with back pain
Closeup rear low angle view of an early 60’s senior gentleman having some back pain. He’s at doctor’s office having medical examination by a male doctor. The patient is pointing to his lumbar region.
Researchers evaluated the association between Assessment of Spondyloarthritis International Society Health Index (ASAS-HI) and disease activity and burden in patients with spondyloarthritis.

Health impairment in patients with spondyloarthritis (SpA) was found to be associated with high disease activity, worsening functionality, and concomitant fibromyalgia, according to study results published in Clinical and Experimental Rheumatology.

Chronic inflammatory diseases that have common clinical, genetic (association with the human leukocyte antigen [HLA]-B27 antigen), and pathophysiologic features affecting the axial skeleton and have peripheral and extra-articular manifestations (such as uveitis, psoriasis, and inflammatory bowel disease) are included in the SpA spectrum. Patients with SpA experience pain, stiffness, fatigue, and limitations in mobility, all of which affect their daily activities and quality of life. The Assessment of Spondyloarthritis International Society Health Index (ASAS-HI) has been developed and recently validated to assess the health status of patients with SpA, including addressing pain, emotional functions, sleep, sexual function, mobility, self-care, and community life.

To assess the clinical use of ASAS-HI on disease activity, disease burden (functionality and mobility), and structural damage in SpA, the researchers included specific SpA disease assessment tools in the current observational, cross-sectional study. These tools were the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and University of Cordoba Ankylosing Spondylitis Metrology Index (UCOASMI) to evaluate structural spine damage; the Bath Ankylosing Spondylitis Metrology Index (BASMI) to evaluate mobility; the Bath Ankylosing Spondylitis Functional Index (BASFI) to evaluate functionality; the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the ASAS-endorsed Disease Activity Score (ASDAS) to evaluate disease functionality; and the Fibromyalgia Rapid Screening Tool (FIRST) to detect fibromyalgia syndrome.

A total of 126 patients (65.9% men) from Reina Sofia University Hospital in Spain were included in the analysis. Mean ASAS-HI score was 4.6±3.9, which indicated a “strong” positive linear correlation (r>0.70) with BASDAI and BASFI and a “moderate” positive linear correlation (r=0.40-0.70) with visual analog score (VAS) and ASDAS.

Researchers noted that patients with vs without a suspicion of concomitant fibromyalgia showed higher ASAS-HI, ASDAS C-reactive protein (CRP), and global VAS scores (P <.05 for all).

Using multiple linear regression, the researchers demonstrated that ASAS-HI was independently associated with disease activity (BASDAI; β=0.62; 95% CI, 0.25-0.97; P =.001), functionality (BASFI; β=0.57; 95% CI, 0.26-0.88; P =.001), and the presence of possible concomitant fibromyalgia (FIRST; β=2.23; 95% CI, 0.73-3.80; P =.004).  

Overall, the researchers noted that only subjective indices, such as patient-reported outcomes (PROs), and not objective indices, such as mSASSS and UCOASMI, were associated with the health of patients with SpA.

While authors were able to limit subjectivity and intra- and interobserver variability by using the UCOASMI index, they noted some study limitations. The limitations were that the cross-sectional study design did not allow for long-term risk factor determination and having 1 rheumatologist evaluate the mSASSS.

“[Fibromyalgia] can coexist with SpA, worsening the quality of life of these patients and therefore impacting the scores on questionnaires used for evaluation of the patients and PROs. This could influence therapeutic decisions,” the researchers concluded.


Larrubia MÁP, Villegas MCC, Castro RO, et al. ASAS Health Index in patients with spondyloarthritis and its association with disease activity and disease burden including fibromyalgia. Clin Exp Rheumatol. 2021;39(3);Suppl 130:82-88.