Background Rheumatoid arthritis (RA) is a chronic progressive disease that can have profound influence on working capacity of affected people. It has been highlighted that reduced productivity is one of the major issue in RA and represents a significant economic burden on the patients, their families, and society.

Objectives The objective of this study was to estimate the impact of biologic therapy on self-reported working capacity in Serbian patients with RA.

Methods During the period from November 1 to December 15, 2015, 315 consecutive RA patients who were treated in one of three randomly chosen Serbian clinics were enrolled in a cross-sectional study. The inclusion criteria were: age ≥18 years, diagnosis of RA of at least 6 months, current MTX use for at least 1 month (with or without concomitant usage of biologic therapy), and written informed consent. The severity of pain is estimated by visual analogue scale (VAS). The differences between groups were assessed using the Mann-Whitney U-test. The relationships between the biologic therapy-related changes in productivity and the indicated parameters were evaluated using the Spearman rank correlation.

Results Distribution of study sample regarding the employment status showed that 26.3% of the responders were employed, 23.5% were unemployed, while 50.2% were retired. The analysis of self-reported working ability demonstrated that 25.4% of the RA patients stated full work capacity, 38.1% partial work capacity, while 36.5% of the participants reported inability to work. Work incapacity was statistically significantly correlated with following variables: duration of RA (ρ=0,136; p=0,016), duration of MTX treatment (ρ=0,179; p=0,001) and the use of biologic therapy (ρ=-0,134; p=0,017). More than half (51.7%) of RA patients used biologic therapy. The average value of VAS score in the group currently receiving biologic therapy was 48.6±28.8 mm, while in the group that was not receiving a biological therapy was 61.3±25.1 mm, with statistically significant difference between these two groups (Z =-3.948; p<0.001). The majority of the participants (82.2%) who used biologic drug reported an improvement of working capacity following the introduction of this therapy. Also, more than half of these patients (53.4%) stated that the increase of working capacity occurred after 4 weeks of biologic therapy initiation.

Conclusions The results of our study suggested that biologic therapy deeply and rapidly improved working capacity in patients with RA. Keeping in mind the fact that the loss of working ability is a significant outcome of RA, the effectiveness of treatment strategies should be evaluated not only using traditional clinical, functional, and radiographic measures, but also by establishing the possible influence of these treatments on working ability in this group of patients.

Disclosure of Interest S. Zivojinovic: None declared, S. Stojanovic: None declared, M. Lazarevic: None declared, S. Mamula Masic Grant/research support from: The research was sponsoed by Roche d.o.o., Employee of: Roche d.o.o., N. Damjanov: None declared