Patients with rheumatoid arthritis (RA) who begin anti-tumor necrosis factor (TNF) therapy within 5 years of disease onset are more likely to regain work ability within 3 years of treatment compared with patients who started the therapy later, according to recent research published in the Annals of the Rheumatic Diseases.
Tor Olofsson, MD, from the rheumatology section and Department of Clinical Sciences Lund at Lund University in Sweden, and colleagues identified 753 patients with RA in the Anti-Rheumatic Treatment in Sweden biologics register with no working ability before beginning anti-TNF therapy and compared them with 1048 patients with RA with full work ability before anti-TNF therapy, according to the article.
High-Yield Data Summary
- Initiation of anti-TNF therapy within 5 years of RA disease onset significantly increased the probability of being able to return to work during the next 3 years compared with patients for whom anti-TNF therapy was not initiated as quickly.
Of these, 49% of patients (n = 512) in the group with full work ability and 35% of patients in the group with no work ability had been diagnosed with RA for less than 5 years.
No work ability was defined as having 90 days of sick leave or disability pension within 3 months in the Social Insurance Agency in Sweden, and a 50% or greater improvement in work ability compared with treatment start was the primary outcome. The researchers measured Health Assessment Questionnaire score, Disease Activity Score 28, disease duration, age, sex, employment, and education level at baseline.
Within 3 years of beginning anti-TNF therapy, patients with no work ability had a 35% probability of regaining work ability if starting treatment within 5 years of RA onset, whereas there was a 14% probability of regaining work ability if patients started treatment after 5 years of RA disease onset (adjusted hazard ratio, 2.1; 95% confidence interval, 1.4-3.2).
“Furthermore, patients without a history of hip-knee replacement at anti-TNF start had more work ability gain and less work ability loss, while patients with high [Health Assessment Questionnaire] and high [Disease Activity Score 28] values had a higher risk of losing work ability,” the researchers wrote.
In the group of patients with full work ability, there were no significant differences between loss in work ability for patients who had onset of RA at less than 5 years or 5 years or more.
Summary and Clinical Applicability
“Exploring the relationship between disease duration and disability pension status in RA-patients with no work ability at bio-start, a close association was found: the longer the disease duration at anti-TNF start, the higher the share of patients with full-time disability pension,” the researchers wrote.
The researchers noted disability pension status was a strong predictor of return to work ability in patients with no work ability, but disease duration was no longer significant when adjusting for this factor in a multivariate analysis.
“Additional analyses though showed an almost fivefold increase in the risk of being on full-time disability pension for patients with disease duration ≥5 years at bio-start compared with patients starting treatment earlier,” Dr Olofsson and colleagues wrote. “Once on full-time disability pension, very few patients regain any work ability.”
- Researchers noted leave and disability pension were the only work disability data available to them, sick leave data were only available until 2010, and sick leave episodes longer than 2 weeks were not captured; variables such as working hours, work environment, demands of a physical job, financial situation, and coping ability were not measured and could potentially weaken results
- Applicability of the study results internationally may be limited because of Sweden’s welfare system differing from other countries.
Dr Askling is a paid researcher for UCB, Roche, Merck, Pfizer, Samsung, Lilly, and AbbVie, and has received compensation from Lilly for an ad board. Dr Eriksson is a paid researcher for Novo Nordisk and COMBINE Sweden and is an external consultant for AbbVie. Dr Englund has been on advisory boards for Pfizer and Abbott, and has received compensation for research projects from Schering-Plough, AstraZeneca, Novo Nordisk, Pfizer, and Roche. Dr Jacobsson is on the speaker’s bureau for Pfizer, Novartis, AbbVie, and Celgene. Dr Petersson receives ownership options from Ana Mar.
Olofsson T, Petersson IF, Eriksson JK, et al. Predictors of work disability after start of anti-TNF therapy in a national cohort of Swedish patients with rheumatoid arthritis: does early anti-TNF therapy bring patients back to work? [published online January 10, 2017]. Ann Rheum Dis. doi: 10.1136/annrheumdis-2016-210239