Costs and work limitation of patients with ankylosing spondylitis in China.

OBJECTIVES: To access the annual direct, indirect costs and work limitation of AS patients in Chinese population and explore the determinants of cost. METHODS: A retrospective, cross-sectional study was performed in 257 patients with AS in China. The participants completed questionnaires about disease characteristics, quality of life and direct and indirect costs. Only the patients with paid-work completed the Work Limitation Questionnaire (WLQ), a 25-item questionnaire that accesses the impact of chronic health conditions on job performance and productivity. Functional impairment and disease activity were assessed using the Bath Ankylosing Spondylitis Functional Index (BASFI) and the Bath Akylosing Spondylitis Disease Activity Index (BASDAI). Quality of life was measured by the Short Form-36. RESULTS: Of the 257 patients who completed the questionnaires, the mean age was 28.5 (SD=0.5) with mean disease duration of 6.52 years (SD=0.44). The mean BASDAI and BASFI score was 3.28 and 1.3, respectively. Among the 257 patients, 21.8% are students, 64.2% have a paid job and 10.5% without a job because of AS. 165 participants finished the WLQ with a mean WLQ index of 0.19 which corresponds to a 17% decrease in productivity. The annual estimated costs of each patient was $2714.18 while the indirect cost accounted for 64.7%. The annual direct cost significantly correlated with disease activity. CONCLUSIONS: Our research is the first to provide information about the burden of AS and the work status of AS patients in mainland China, which may help to establish the treatment strategy and a policy of support.

Evaluation of Assessment of Spondyloarthritis International Society classification criteria for axial spondyloarthritis in Chinese patients with chronic back pain: results of a 2-year follow-up study.

OBJECTIVE: To evaluate the diagnotic value of the Assessment of Spondyloarthritis International Society (ASAS) classification criteria for axial spondyloarthritis (SpA) in Chinese patients with chronic back pain and without radiographic sacroiliitis in a 2-year follow-up study. METHODS: Patients with chronic back pain ≥ 3 months, onset age ≤ 45 years and without radiographic sacroiliitis were enrolled, and then received 2-year follow-up. All the clinical parameters associated with SpA were recorded. The patients were followed for 2 years and the final diagnosis of axial SpA or non-SpA was confirmed by rheumatologists. Diagnostic concordance between the initial classification according to three classification criteria (ASAS criteria for axial SpA, European Spondylarthropathy Study Group (ESSG) criteria and Amor criteria) and final diagnosis was compared. Diagnostic sensitivity and specificity were compared between the two subsets of ASAS criteria (set 1: sacroiliitis plus more than one SpA feature; set 2: HLA-B27 plus two more SpA features). RESULT: One thousand and sixty-eight patients entered the study and 867 completed the 2-year follow-up (455 axial SpA and 412 non-SpA). The concordance of ASAS criteria was better than ESSG and Amor criteria. Three hundred and thirty-three patients and 335 patients were classified as axial SpA according to the ASAS set 1 and set 2 of criteria, respectively. Further, set 1 of criteria (318/333) showed higher specificity than set 2 critera (279/335) (P = 0.000). CONCLUSION: The ASAS classification criteria for axial SpA showed good concordance in diagnosing Chinese axial SpA patients in this prospective study. Set 1 criteria involving sacroiliitis plus more than one SpA feature had better diagnosing value.