Assessment of work instability in spondyloarthritis: a cross-sectional study using the ankylosing spondylitis work instability scale

OBJECTIVES: Work status is an important outcome in SpA. The objective was to assess work instability and its determinants in a cohort of patients with SpA, using the AS-work instability scale (AS-WIS). METHODS: We performed a cross-sectional monocentre study. Patients were definite SpA patients with paid work. Work instability was measured by the AS-WIS. Its determinants were assessed by correlations with SpA scores (BASDAI, BASFI and patient's global assessment) and patients with low work instability (AS-WIS score < 11) were compared with those with moderate to high instability, through backward logistic regression. RESULTS: In all, 156 patients were assessed: mean (s.d.) age 41 (11) years, mean disease duration 15 (11) years; 71 (45.5%) were on TNF blockers. The mean AS-WIS score was 9.5 (5.5); 55 (35%) patients had moderate and 8 (5%) patients had high work instability. Correlations of the AS-WIS score with SpA scores were significant but moderate (BASDAI R = 0.42, BASFI R = 0.41, patient's global assessment R = 0.53; P < 0.0001). In multivariate analysis, high patient's global assessment was the only element associated with moderate to high work instability; demographic characteristics and treatments were not significant elements. CONCLUSION: Work instability was found to be high and its main determinant was patient's global assessment. The predictive validity of the AS-WIS in terms of job retention should be further assessed.