Fatigue Contributes to Work Productivity Impairment in Patients with Axial Spondyloarthritis: a Cross-sectional UK Study

Objectives: To determine factors associated with absenteeism, presenteeism, work productivity loss (WPL), and daily activity impairment in UK patients with AxSpA using standardised measures.

Methods: 490 patients with AxSpA completed (1) Work Productivity and Impairment questionnaire (WPAI), providing measures for absenteeism, presenteeism, WPL and daily activity impairment, and (2) BASDAI, BASFI, BASMI, Jenkins Sleep scale, Patient Global Assessment disease activity (PGA), back pain night and anytime, EQ-5D for mobility, self-care, daily activities, pain/discomfort, anxiety/depression, EQ-VAS Health State Today, FACIT fatigue, for health-related disease factors. Multivariate linear and logistic regression determined associations between WPAI measures and health-related factors.

Results: 301(61%) patients provided WPAI measurements, 76% were male, 87% HLA-B27+. Mean (SD) WPAI scores for absenteeism were 5.1%(19.2), presenteeism 22%(24.3), WPL 23.2%(25.7), activity impairment 34.8%(27.3). Absenteeism was associated with higher fatigue levels and more likely in patients with nrAxSpA. Presenteeism and WPL were both associated higher fatigue levels, BASDAI, and BASFI respectively. Daily activity impairment was associated with higher fatigue levels, BASFI, PGA, EQ-VAS, and smoking.

Conclusions: Work productivity and impairment are associated with fatigue, disease activity, and functional ability in UK patients with AxSpA. The strong association of fatigue with all work measures as well as with daily activity impairment emphasises the need to better understand the impact of fatigue on patients' quality of life. Improving fatigue may help to optimise work status.