title: Comparison of the efficacies of abatacept and tocilizumab in patients with rheumatoid arthritis by propensity score matching.
abstract: OBJECTIVE
  To compare the clinical outcomes at 1 year after the treatment with either abatacept or tocilizumab in patients with rheumatoid arthritis in routine clinical practice.
  
  
  METHODS
  To overcome potential bias in allocation to treatment with abatacept or tocilizumab, a propensity score based on multiple baseline characteristics variables was calculated and 102 of 194 patients treated with abatacept and 102 of 273 patients treated with tocilizumab were statistically extracted. Clinical outcomes were assessed.
  
  
  RESULTS
  The baseline characteristics were statistically comparable. At week 52, 72%/69% of patients (abatacept/tocilizumab) were still receiving treatment. The Simplified Disease Activity Index (SDAI) decreased from 28.7/27.7 at baseline to 14.0/12.5 at week 52 with abatacept/tocilizumab, respectively. At week 52, the remission rates for abatacept/tocilizumab were 18%/20%, respectively. No statistical difference in clinical efficacy between abatacept and tocilizumab was seen. Moreover, a subanalysis showed that abatacept and tocilizumab had similar effectiveness with or without methotrexate. However, prognostic factors at baseline contributing to the Clinical Disease Activity Index at week 52 were different between the two groups by multiple regression analysis. A higher rheumatoid factor (RF) titre and lower SDAI at baseline were associated with lower SDAI at week 52 in patients treated with abatacept, whereas patients receiving tocilizumab with a lower Health Assessment Questionnaire Disability Index and who were biologics-naïve at baseline had a lower SDAI at week 52.
  
  
  CONCLUSIONS
  We compared patients treated with abatacept or tocilizumab after statistical adjustment by propensity score matching. Clinical efficacies, including SDAI, were comparable in both treatment groups. However, the predictive factors were different: abatacept appears to benefit patients with higher RF titres, and early induction of tocilizumab is an important factor for good clinical efficacy.
authors.affiliation: The First Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kubo
authors.affiliation: The First Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Nakayamada
authors.affiliation: The First Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Nakano
authors.affiliation: The First Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Hirata
authors.affiliation: The First Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Fukuyo
authors.affiliation: The First Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Ippei
authors.initials: I
authors.lastname: Miyagawa
authors.affiliation: The First Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Hanami
authors.affiliation: The First Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Saito
authors.affiliation: The First Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000069594:Abatacept / Q000627:therapeutic use*; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000188:drug therapy*; D001688:Biological Products / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D008875:Middle Aged; D057216:Propensity Score; D012217:Rheumatoid Factor / Q000097:blood; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D018501:Antirheumatic Agents; D001688:Biological Products; D000069594:Abatacept; D012217:Rheumatoid Factor; C502936:tocilizumab; D008727:Methotrexate
keywords: DMARDs (biologic); Outcomes research; Rheumatoid Arthritis