Do quality of life and work productivity change in early axial spondyloarthritis and non-axial spondyloarthritis patients after two years?

OBJECTIVE: To compare health-related quality of life (HRQoL) and work productivity in axial spondyloarthritis (axSpA) and non-axSpA patients with chronic back pain of < 2 years (2 y). METHODS: Baseline and 2 y data of patients included in the SPondyloArthritis Caught Early cohort were analyzed. 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 y outcomes between groups (axSpA and non-axSpA), adjusting for the baseline value, sex, age and use of nonsteroidal anti-inflammatory drugs. 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 y, PCS, presenteeism, WPL and AI significantly improved in both groups; absenteeism only 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 still after 2 y. Although most outcomes improve in both groups, axSpA is associated with larger improvements in work productivity and activity impairment.