Background Patients with ankylosing spondylitis have decreased work productivity (WP). The association between WP and (early) axial Spondyloarthritis (axSpA) is relatively unexplored. The aim of the SpondyloArthritis Caught Early (SPACE)-cohort is to diagnose axSpA early and to assess the burden of disease in these chronic back pain patients.
Objectives To describe the WP over one year in patients with axSpA and other forms of chronic back pain included in the SPACE-cohort.
Methods The SPACE-cohort includes patients with chronic back pain (≥3 months, ≤2 years, onset <45 years) recruited from 5 participating centres in Europe1. With the Work Productivity and Activity Impairment questionnaire (WPAI) the impact of axSpA on WP in the past seven days was assessed at baseline and one year. Three summary scores were calculated; absenteeism (i.e. absence at work due to disease), presenteeism (i.e. decreased functionality at work due to disease), and work productivity loss (WPL; i.e. total work impairment due to disease). Greater impairment is indicated by higher scores2.
Results In total, 91 patients had data at both baseline and one year and 68 of these patients (74.7%) had a paid job at both time points. Patients were classified according to the ASAS axSpA classification: no axSpA (i.e. no axSpA features, n=9), possible axSpA (i.e. not fulfilling the criteria but ≥1 axSpA features, n=22), axSpA clinical arm (n=25), and axSpA imaging arm (n=12). At baseline, patients worked on average 27.3 hours (SD 13.5) and missed a mean of 3.0 hours (SD 6.5) at work due to chronic back pain in the past seven days. After 1 year, average working time in the past seven days and average working time that was missed due to chronic back pain was quite stable (28.2 hours (SD 14.0) and 3.5 hours (SD 8.5) respectively). Table 1 shows that the mean % of presenteeism is the highest in no axSpA and possible axSpA patients (40.0% and 46.4% at baseline, 38.9% and 35.0% at 1 year, respectively), compared to patients fulfilling the clinical arm and imaging arm of the ASAS axSpA criteria (37.2% and 33.3% at baseline, 27.2% and 25.0% at 1 year, respectively). At baseline, absenteeism is the highest in possible axSpA patients (13.4%) and the lowest in patients fulfilling the imaging arm of ASAS axSpA criteria (2.4%). Absenteeism increases over a period of 1 year in all groups, except in the possible axSpA group. Mean % of WPL is highest in no axSpA and possible axSpA. WPL decreased over 1 year in all groups, except in the no axSpA group.
Conclusions Chronic back pain has a substantial impact on presenteeism, absenteeism, and WPL irrespective of the cause of back pain complaints (e.g. axSpA or not). However, in comparison WP in patients with axSpA was less bad than in patients with possible axSpA or no axSpA. In general, there was a slight tendency to improvement of WP over a one-year period except in the no axSpA group, but in all patients including early axSpA WP loss remained considerable.
van den Berg R, Rheumatology 2013;52:1492-9.
Reilly MC, Pharmacoeconomics 1993;4:353-65
Disclosure of Interest None declared