Background Patients with ankylosing spondylitis (AS) and jobs can experience difficulties in coping with the demands of their work.
Objectives To assess the effect of etanercept (ETN) after 6 and 12 months on work-related outcomes in patients with active AS and paid employment.
Methods A prospective, multicenter, open-label, observational study. The effect of ETN on work outcomes was assessed using the change from baseline (BL) at 6 and 12 months in the Work Productivity & Activity Impairment (WPAI) scale components (absenteeism, impairment, overall work impairment and activity impairment). In addition, the following assessments were performed at BL, 6 and 12 months: Physician Global Assessment (PGA), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Patient Global Score (BAS-G), Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP, ASDAS-ESR, EuroQoL-5 Dimension (EQ-5D) utility score and Visual Analogue Scale (VAS) and Short Form (SF)-36 health survey; regression models were used to determine how the change from BL in these assessments influenced the outcome of WPAI.
Results 80 patients with AS and jobs were included in the study; 40 (50%) were male, with a mean age of 38.1 years (SD, 9.1) and mean disease duration (symptoms) of 10.8 years (SD, 8.8). WPAI scores were 35% for absenteeism, 49% for impairment, 54% for overall work impairment and 63% for activity impairment at BL. At follow-up, 74 (93%) and 67 (84%) patients participated at 6 and 12 months, respectively. After 6 months of ETN treatment, significant improvements from BL were observed in all WPAI components (P<0.0001; Table). The significant improvements in WPAI components continued to 12 months (P<0.0001 for all). Improvements across all WPAI components at 6 months were associated with improvements in BASDAI, BASFI, BAS-G, ASDAS-ESR, SF-role physical, SF-bodily pain and SF-role emotional (r=0.27 to 0.64; P<0.05 for all) but were not associated with changes in PGA, BASMI, ASDAS-CRP, EQ-5D VAS, EQ-5D utility, SF-physical functioning, SF-general health, SF-vitality, SF-social functioning or SF-mental health. After 12 months, improvements in all WPAI components showed correlations with improvements in BASDAI, SF-physical functioning and SF-role physical (r=0.28 to 0.66; P<0.05 for all) but not with any other outcome measure.
Conclusions In this study, ETN treatment for 6 and 12 months effectively reduced the work-related difficulties experienced in patients with AS. Improvements from BL in a number of measures of pain, disease activity, and physical function were associated with improvements across all WPAI components.
Acknowledgements This study was sponsored by Pfizer Inc. Medical writing support was provided by Kim Brown of UBC Scientific Solutions and was funded by Pfizer Inc.
Disclosure of Interest A. Boonen Grant/research support from: MSD, Pfizer, Amgen, Abbott, Speakers bureau: Pfizer, UCB, C. Boone Employee of: Pfizer Inc, A. Albert Grant/research support from: Pfizer Inc., H. Mielants Consultant for: MSD, UCB and Pfizer, Speakers bureau: MSD, UCB and Pfizer