Patients with rheumatoid arthritis treated with tumour necrosis factor antagonists increase their participation in the workforce: potential for significant long-term indirect cost gains (data from a population-based registry)
- 1Department of Medicine, Rheumatology Unit, Karolinska Institute, Karolinska University Hospital Solna, Stockholm, Sweden
- 2Department of Medicine, Centre for Pharmacoepidemiology, Karolinska Institute, Stockholm, Sweden
- 3Department of Woman and Child Health, Childhood Cancer Research Unit, Karolinska Institute, Stockholm, Sweden
- Correspondence to J Augustsson, Department of Medicine, Rheumatology Unit, Karolinska Institute, Karolinska University Hospital Solna, Stockholm, SE-171 76, Sweden; jenny.augustsson{at}ki.se
- Accepted 30 April 2009
- Published Online First 25 May 2009
Abstract
Objective: To investigate the effect of tumour necrosis factor (TNF) antagonist treatment on workforce participation in patients with rheumatoid arthritis (RA).
Methods: Data from the Stockholm anti-TNFα follow-up registry (STURE) were used in this observational study. Patients with RA (n = 594) aged 18–55 years, (mean (SD) 40 (9) years) followed for up to 5 years were included with hours worked/week as the main outcome measure. Analyses were performed unadjusted and adjusted for baseline age, disease duration, Health Assessment Questionnaire (HAQ), 28-joint Disease Activity Score (DAS28) and pain score.
Results: At baseline patients worked a mean 20 h/week (SD 18). In unadjusted analyses, significant improvements in hours worked/week could already be observed in patients at 6 months (mean, 95% CI) +2.4 h (1.3 to 3.5), with further increases compared to baseline at 1-year (+4.0 h, 2.4 to 5.6) and 2-year follow-up (+6.3 h, 4.2 to 8.4). The trajectory appeared to stabilise at the 3-year (+6.3 h, 3.6 to 8.9), 4-year (+5.3 h, 2.3 to 8.4) and 5-year follow-up (+6.6 h, 3.3 to 10.0). In a mixed piecewise linear regression model, adjusted for age, sex, baseline disease activity, function and pain, an improvement of +4.2 h/week was estimated for the first year followed by an added improvement of +0.5 h/week annually during the years thereafter. Over 5 years of treatment, the expected indirect cost gain corresponded to 40% of the annual anti-TNF drug cost in patients continuing treatment.
Conclusion: Data from this population-based registry indicate that biological therapy is associated with increases in workforce participation in a group typically expected to experience progressively deteriorating ability to work. This could result in significant indirect cost benefits to society.
Footnotes
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Funding JA was funded by Apotekt Farmaci AB. The funding sources did not read or comment on any version of the manuscript, nor influence the analyses in any way.
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Competing interests None.
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Ethics approval The ethics committee at the Karolinska Institute, Stockholm, Sweden, approved the study.
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JA and RFV conceived the hypothesis for the manuscript and conducted the initial statistical analyses. JA wrote the first draft of the manuscript and had the main responsibility for the manuscript process. MN contributed to statistical analyses, health economics and the manuscript. CCC contributed to data collection and SE contributed to the statistical analyses. CCC, MN, RFV and SE and provided critical input at all stages and critically reviewed and contributed to the final draft. All authors are guarantors.
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Provenance and Peer review Not commissioned; externally peer reviewed.
