Clinical utility of the ASDAS index in comparison with BASDAI in patients with ankylosing spondylitis (Axis Study)

Abstract

The objective of the study was to study the clinical utility of the Ankylosing Spondylitis Disease Activity Score (ASDAS) for the assessment of disease activity in ankylosing spondylitis (AS) patients, compared to the Bath Ankylosing Spondylitis Activity Index (BASDAI). This was a prospective longitudinal observational study in patients with AS (NY-modified criteria) from 23 Spanish centers. Physical and analytical data; global, lumbar, and nocturnal pain; ASDAS, BASDAI and minimally acceptable clinical status (PASS) were collected. Psychometric characteristics of both indexes were analyzed: construct validity (convergent and divergent), discriminant capacity, criterion validity (global physician and patient assessment), and sensitivity to change. The study involved 127 patients (19.7% attrition). Both BASDAI and ASDAS showed a higher correlation with patient's global assessment (r = 0.76 and 0.70, respectively) than with physician's global assessment (r = 0.67 and 0.57). Both scores allowed discriminating patients with an acceptable clinical status, although BASDAI to a greater extent than ASDAS (Cohen δ 1.72 vs 0.88 for the medical PASS). Both scores showed sensitivity to change in patients who changed from an unacceptable symptomatic state to acceptable according to PASS criteria (physician and patient) and by BASDAI 50 response criteria (Cohen δ > 0.80). BASDAI showed better criterion validity than ASDAS, both for the patient PASS (AUC 0.85 vs 0.79) and for the physician's (AUC 0.90 vs 0.79). ASDAS shows adequate performance for disease activity in patients with AS; however, in this study, its psychometric properties do not present advantages over BASDAI in terms of criterion validity, sensitivity to change or discriminative capacity; replacement of BASDAI by ASDAS is not supported by the data.

Meta-Analysis of Changes in the Number and Proportion of Regulatory T Cells in Patients with Ankylosing Spondylitis

“…Although studies have confirmed that ASDAS and BASDAI are highly correlated, they are good measures of AS disease activity [71,72]. But, BASDAI measures disease activity from the patient's perspective, while ASDAS included not only the patient's opinion but also objective measures, such as C Reactive Protein (CRP), and allows measurement of disease activity at any given time point.…”

Ankylosing Spondylitis Disease Activity Score (ASDAS): 2018 update of the nomenclature for disease activity states

“…A previous study by Rodríguez-Lozano et al 7 suggested cut-off values between 2.5 and 3.0 for ASDAS-CRP and cut-off values between 2.8 and 3.5 for ASDAS-ESR (PASS as external construct), depending on the method used to determine the cut-off value. A more recent study by Sellas et al 8 suggested that the ASDAS cut-off of 2.04 was associated with patient-PASS while the ASDAS cut-off of 2.44 was associated with physician-PASS.…”

Use of Quantitative Vertebral Bone Marrow Fat Fraction to Assess Disease Activity and Chronicity in Patients with Ankylosing Spondylitis

“…However, it is based on self-reported nonspecific symptoms such as the severity of inflammatory low back pain, fatigue, and quality of life [2]. While conventional laboratory inflammatory markers such as elevated CRP and ESR can provide objective information, their sensitivity and specificity are not satisfactory [27,28]. The ASDAS consists of both subjective questionnaires and objective laboratory inflammatory markers; however, both can be affected by various other medical conditions [14].…”