Abstract
OBJECTIVE: The objective of this study was to compare health-related quality of life (HRQoL) and work productivity in axial SpA (axSpA) and non-axSpA patients with chronic back pain of <2 years. METHODS: Baseline and 2-year data for patients included in the SPondyloArthritis Caught Early cohort were analysed. HRQoL was assessed by the physical (PCS) and mental component summary (MCS) scores of the 36-Item Short-Form Health Survey, and presenteeism, absenteeism, work productivity loss (WPL) and activity impairment (AI) by the Work Productivity and Activity Impairment questionnaire. Linear or zero-inflated negative binomial regression was conducted to compare 2-year outcomes between groups (axSpA and non-axSpA), adjusting for the baseline value, sex, age and use of NSAIDs. RESULTS: There were 265 axSpA and 108 non-axSpA patients: males 52% vs 26%, mean age 29 vs 31 years, respectively. At baseline, non-axSpA patients showed worse PCS (mean 28.6 axSpA vs 26.6 non-axSpA), presenteeism (31.1% vs 37.3%), absenteeism (8.2% vs 10.3%), WPL (34.7% vs 44.1%) and AI (39.6% vs 48.5%). MCS was not impaired in either group. After 2 years, PCS, presenteeism, WPL and AI significantly improved in both groups; absenteeism only improved in axSpA. In multivariable analysis, axSpA (vs non-axSpA) was associated with 22% less WPL [incidence rate ratio (95% CI): 0.78 (0.62; 0.98)] and 18% less AI [0.82 (0.69; 0.97)]. CONCLUSION: HRQoL and work productivity are more impaired in non-axSpA (vs axSpA) at baseline and also after 2 years. Although most outcomes improve in both groups, axSpA is associated with larger reductions in WPL and AI.