Functional disability can deteriorate despite suppression of disease activity in patients with rheumatoid arthritis: a large observational cohort study

Abstract

Objective To analyze the relationship between the progression of disability and disease activity in patients with rheumatoid arthritis (RA) in daily practice.

Methods Patients from an observational cohort, IORRA, who completed surveys during 2009–2011 were eligible. Linear regression of disease activity score 28 (DAS28), Japanese version of Health Assessment Questionnaire (J-HAQ), and EQ-5D from baseline were calculated, and the angles of the regression lines were designated DAS28 slope, J-HAQ slope, and EQ-5D slope, respectively, in each patient; averages were compared between treatment groups.

Results A total of 5,038 patients [84.0 % female, mean age 59.4 (SD 13.1) years, disease duration 13.2 (9.6) years, DAS28 3.29 (1.14), and J-HAQ 0.715 (0.760)] were analyzed. The average DAS28 slope indicated improvement in all groups, whereas J-HAQ slopes were negative in patients on methotrexate (MTX), biologics, combination biologics/disease-modifying antirheumatic drugs (DMARDs), and combination biologics/MTX at baseline, but positive in patients on prednisolone >5 mg/day [0.010 (0.153)] and not on MTX at baseline [0.007 (0.122)], representing a worsening of disability.

Conclusion There is some disparity between improvement of disease activity and progression of disability, suggesting that quality of remission must be considered.

Keywords::

• Rheumatoid arthritis
• Disease activity
• Physical function
• Treatment
• Cohort study

Electronic supplementary material

The online version of this article (doi:10.1007/s10165-012-0816-5) contains supplementary material, which is available to authorized users.

Electronic supplementary material

The online version of this article (doi:10.1007/s10165-012-0816-5) contains supplementary material, which is available to authorized users.

Acknowledgments

The authors thank all members involved in the administration of the IORRA cohort database.

Conflict of interest

This study was partly supported by a research grant from the Ministry of Health, Welfare and Labor Japan. The IORRA cohort was supported by unrestricted research grants from 36 pharmaceutical companies: Abbott Japan, Asahikasei Kuraray Medical, Asahikasei Pharma, Astellas Pharma, AstraZeneca, MSD, Chugai Pharmaceutical, Daiichi Fine Chemical, Daiichi Sankyo, Dainippon Sumitomo Pharma, Eisai, GlaxoSmithKline, Janssen Pharmaceutical, Japan Tobacco, Kaken Pharmaceutical, Kissei Pharmaceutical, Kowa Pharmaceutical, Mitsubishi Chemical Medience, Mitsubishi Tanabe Pharma, Nippon Chemiphar, Nippon Shinyaku, Novartis Pharma, Otsuka Pharmaceutical, Pfizer, Sanofi-Aventis, Santen Pharmaceutical, Sanwa Kagaku Kenkyusho, Sekisui Medical, Taisho Toyama Pharmaceutical, Takeda Pharmaceutical, Teijin Pharma, Torii Pharmaceutical, Toyama Chemical, UCB Japan, and Zeria Pharmaceutical. YS has received speaking fees from Abbott Japan, Chugai Pharmaceutical, Eisai, Mitsubishi Tanabe Pharma, and Pfizer. ET has received speaking fees and/or consulting fees from Abbott Japan, Astellas Pharma, Bristol–Myers Squibb, Chugai Pharmaceutical, Eisai, Mitsubishi Tanabe Pharma, Pfizer, Santen Pharmaceutical, and Takeda Pharmaceutical. AN has received speaking fees and/or consulting fees from Abbott Japan, Astellas Pharma, Chugai Pharmaceutical, Eisai, Janssen Pharmaceutical, Mitsubishi Tanabe Pharma, Pfizer, Sanwa Kagaku Kenkyusho, and UCB Japan. AT has received speaking fees from Abbott Japan, Bristol–Myers Squibb, Eisai, Mitsubishi Tanabe Pharma, Pfizer, Takeda Pharmaceutical, Teijin Pharma, and Torii Pharmaceutical. SM has received speaking fees from Chugai Pharmaceutical, Eisai, and Mitsubishi Tanabe Pharma. HY has received consultant fees, speaking fees, and/or honoraria from Chugai Pharmaceutical, Daiichi Sankyo, Mitsubishi Tanabe Pharma, Abbott Japan, Eisai, Takeda Pharmaceutical, Janssen Pharmaceutical, Hoffmann-La Roche, and Pfizer. All other authors have declared no conflicts of interest.