To examine whether clinical benefits observed after treatment with infliximab were accompanied by improvement in productivity and reduction in time lost from work in a randomized, double-blind, placebo-controlled, multicenter trial of patients with ankylosing spondylitis (AS).
Adults with active AS receiving standard antiinflammatory treatment were randomly assigned in a 3:8 ratio to receive infusions of placebo or 5 mg/kg infliximab at weeks 0, 2, 6, and every 6 weeks thereafter through week 24. Physical function was measured using the Bath Ankylosing Spondylitis Functional Index. The impact of disease on productivity was measured using a visual analog scale (range 0–10). Self-reported employment status and time lost at work before and during the trial were collected. Spearman's correlation coefficient was used to examine factors associated with productivity.
Patients treated with infliximab had a more significant reduction in limitations of work and daily activity due to physical or emotional problems than patients treated with placebo. Of the subset of patients employed full time, patients in the infliximab group had a significantly greater improvement in productivity as early as week 6 compared with the placebo group. The median change from baseline in the productivity score at week 24 was 0.7 (median percent change 11%) in the placebo group compared with 2.1 (62%) in the infliximab group (P < 0.05). Daily productivity was significantly correlated with physical function and disease activity at baseline and week 24.
The daily productivity of patients with active AS was significantly associated with functional impairment and disease activity. Infliximab treatment significantly improved productivity and reduced workday loss among employed patients with AS.