Background Rheumatoid arthritis (RA) incurs a substantial socioeconomic burden (1). Assessment of the cost-effectiveness of treating RA should take into account the impact on late, costly consequences of RA, such as reduced need for joint replacement surgery (2), and health related quality of life. However, little is known about utility gain in clinical practice, in particular with biologic DMARD (bDMARD) monotherapy.

Objectives To evaluate treatment response with special focus on utility (EQ-5D) and drug adherence of bDMARDs prescribed as monotherapy in RA patients in southern Sweden.

Methods All RA patients registered in the SSATG database as initiating bDMARD as monotherapy, i.e. without concomitant conventional synthetic DMARDs (csDMARDs), from 1st of January 2006 through 31st of December 2012, were eligible for inclusion. Descriptive statistics for effectiveness at 6 months and drug adherence of bDMARD monotherapy were calculated.

Results 758 patients were included (81% women, disease duration: mean 12.6 [SD 11.6]), age: mean 56.7 years [SD 14.1], EQ-5D: median 0.33 [IQR 0.17 to 0.38], and DAS28: mean 5.1 [SD 1.3]). The number of patients starting each bDMARD is given below Figure 1. At 6 months follow-up, the average EQ-5D in patients still on the biologic drug increased by 0.27. The mean improvement in EQ-5D for different bDMARDs ranged from 0.10 to 0.39 (abatacept: 0.39; adalimumab: 0.16; certolizumab: n/a; etanercept: 0.32; golimumab: n/a; infliximab: 0.30; rituximab: 0.10; and tocilizumab: 0.37), but with no statistically significant differences (p=0.92). Overall, DAS28 remission was achieved in 24% and DAS28 defined low disease activity was achieved in 39% of patients. Around one fourth of the patients achieved an ACR50 response (61/259;24%). After 2 years of monotherapy the proportion of patients still on drug was 40%, with the exception of golimumab, certolizumab, and tocilizumab having lower proportions. The estimated drug adherence rates were highest for etanercept and rituximab, but the differences between bDMARDs did not reach statistical significance (Figure 1).

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Conclusions Utility (EQ-5D) increased after 6 months of treatment with a bDMARD in monotherapy, indicating clinically meaningful improvement of patients' quality of life. Remission rates and drug adherence were moderate. Although there were numerical differences between bDMARDs in terms of drug adherence, clinical response and utility gain, no distinct pattern favoured any particular bDMARD when used as monotherapy for RA.

References

1. Lundkvist J, Kastang F, Kobelt G. The burden of rheumatoid arthritis and access to treatment: health burden and costs. Eur J Health Econ 2008 Jan;8 Suppl 2:S49-S60.

2. Kobelt G, Jonsson B. The burden of rheumatoid arthritis and access to treatment: outcome and cost-utility of treatments. Eur J Health Econ 2008 Jan;8 Suppl 2:95-106.

Acknowledgements This study was supported by unrestricted grants from the Oak Foundation, the County of Skåne, Lund University, and the Swedish Rheumatism Association.

Disclosure of Interest T. S. Jørgensen Grant/research support from: research grants paid to institute: AbbVie and Roche, C. Turesson Grant/research support from: unrestricted research grants from Abbvie, Pfizer and Roche., Consultant for: Abbvie, BMS, Janssen, MSD, Pfizer, Roche and UCB, Speakers bureau: Abbvie, BMS, Janssen, MSD, Pfizer, Roche and UCB, M. Kapetanovic: None declared, M. Englund Speakers bureau: honorarium for lectures sponsored by Pfizer, A. Turkiewicz: None declared, R. Christensen Grant/research support from: research grants paid to institute: AbbVie and Roche, H. Bliddal Grant/research support from: research grants paid to institute: AbbVie and Roche, P. Geborek: None declared, L. E. Kristensen Speakers bureau: Abbvie, BMS, Janssen, MSD, Pfizer, Roche and UCB