Biologics improve axial spondyloarthritis patients’ work performance

LIVERPOOL, ENGLAND – Biologic therapy for axial spondyloarthritis can improve individuals’ work productivity and decrease the extent that the disease impairs overall work and overall activity, new data from the British Society for Rheumatology Biologics Register in Ankylosing Spondylitis have shown.

A variety of work outcomes on the Work Productivity and Impairment Specific Health Problem (WPAI-SHP) questionnaire improved to a significantly greater extent with biologics use than without. Presenteeism, or working while sick, improved by a mean of –9.4%. Overall work impairment reduced by 13.9%, and overall activity impairment decreased by 19.2%. There was no great effect on absenteeism, however, with a mean difference in improvement of –1.5% between the groups.

^{Sara Freeman/MDedge News}

Dr. Joanna Shim

“Research into this chronic condition has shown that it has detrimental impact on one’s ability to work,” she added. People may take sick leave and be less productive at work, which can have a psychological effect and cause worry about job loss.

While there is “strong evidence” to show that biologic therapy can improve disease activity in those with axSpA, there is equivocal evidence on whether it has any effect on work outcomes, explained Dr. Shim, a physiotherapist and a postdoctoral research fellow in the Epidemiology Group at the University of Aberdeen (Scotland).

The British Society for Rheumatology Biologics Register in Ankylosing Spondylitis (BSRBR-AS) started recruiting patients with axSpA from 84 centers across the United Kingdom in 2012 and there are now more than 2,500 participants included in the register. Similar to other biologics registers run under the auspices of the British Society for Rheumatology, the BSRBR-AS consists of two cohorts of patients, one who are about to start biologic therapy (with Enbrel [etanercept], Humira [adalimumab], or Cimzia [certolizumab pegol]) and one not receiving biologics.

The current analysis of 577 participants included 161 who had been treated with biologics and 416 who had not. Dr. Shim pointed out that people treated with biologics were younger (42 vs. 47 years), had shorter disease duration (7.7 vs. 12.3 years), and were more likely to be smokers (21% vs. 11%) than were those who had not taken biologics. Biologics-treated patients also had higher mean baseline disease activity measured by the Bath Ankylosing Spondylitis Disease Activity Index (5.8 vs. 3.3), poorer function as measured by the Bath Ankylosing Spondylitis Functional Index (5.4 vs. 2.7), and worse overall Bath Ankylosing Spondylitis Global status scores (6.7 vs. 3.2).

“That’s the reason why they are given biologic therapy in the first place,” Dr. Shim said. To even out these differences, the investigators used propensity score matching before assessing work outcomes with the WPAI-SHP questionnaire. This consists of four components that are assessed in the last 7 days: absenteeism, presenteeism, overall work impairments (a combination of absenteeism and presenteeism), and overall activity impairment.

At recruitment, the investigators found that patients who later received biologics had greater impairment in work outcomes than did patients who later did not receive biologics. Patients who went on to receive biologics reported more absenteeism (13.0% vs. 3.0%), presenteeism (41.5% vs. 19.9%), overall work impairment (43.3% vs. 20.6%), and overall activity impairment (59.9% vs. 32.5%).

“Despite the improvements that we observed, there is still substantial unmet need, in the sense that people in the biologic therapy group are still experiencing significantly higher work impairments, compared to people in the nonbiologic therapy group,” Dr. Shim said. She added that, ideally, there should be no work impairment at all.

Dr. Shim and her associates combined the new BSRBR-AS findings with data from four prior randomized, controlled studies that met criteria for a meta-analysis. The results showed a mean difference between biologic and nonbiologic treatment of –5.35 on presenteeism, –11.20 on overall work impairment, and –12.13 on overall activity impairment. Again, there was little overall effect on absenteeism, with a mean difference of 0.84 between the groups.

The apparent lack of effect of biologic treatment on absenteeism could be from several reasons, one being that absenteeism was reportedly low in the BSRBR-AS and in other studies. Also, there is some evidence that presenteeism precedes absenteeism. The type of work done or number of allowed sick days may also play a role, Dr. Shim suggested.

“Work is a very important economic and social outcome,” Dr. Shim said. “We propose that future work should look into the assessment of work outcomes as standard measures,” in order to generate a greater evidence base around pharmacologic and nonpharmacologic approaches to improve work outcomes.

The BSRBR-AS is funded by the British Society for Rheumatology, which in turn has received function from AbbVie, Pfizer, and UCB. Dr. Shim reported that she had no conflicts of interest in relation to her presentation.