title: Infection risk in patients with rheumatoid arthritis treated with etanercept or adalimumab.
abstract: OBJECTIVE
  To compare the risk of infection for rheumatoid arthritis (RA) patients who took etanercept or adalimumab medication in a nationwide population.
  
  
  METHODS
  RA patients who took etanercept or adalimumab were identified in the Taiwan's National Health Insurance Research Database. The composite outcome of serious infections, including hospitalization for infection, reception of an antimicrobial injection, and tuberculosis were followed for 365 days. A Kaplan-Meier survival curve with a log-rank test and Cox proportional hazards regression were used to compare risks of infection between the two cohorts of tumor necrosis factor (TNF)-α antagonists users. Hazard ratios (HRs) were obtained and adjusted with propensity scores and clinical factors. Sensitivity analyses and subgroup analyses were also performed.
  
  
  RESULTS
  In total, 1660 incident etanercept users and 484 incident adalimumab users were eligible for the analysis. The unadjusted HR for infection of the etanercept users was significantly higher than that of the adalimumab users (HR: 1.93; 95% confidence interval (CI): 1.09-3.42; p=0.024). The HRs were 2.04 (95% CI: 1.14-3.65; p=0.016) and 2.02 (95% CI: 1.13-3.61; p=0.018) after adjusting for propensity scores and for propensity scores in addition to clinical factors, respectively. The subgroup analyses revealed that HRs for composite infection was significantly higher in patient subgroups of older age, female, as well as patients who did not have DM, COPD, and hospitalization history at the baseline.
  
  
  CONCLUSIONS
  In this head-to-head cohort study involving a nationwide population of patients with RA, etanercept users demonstrated a higher risk of infection than adalimumab users. Results of this study suggest the possible existence of an intra-class difference in infection risk among TNF-α antagonists.
authors.affiliation: Department of Pharmacy, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; School of Pharmacy, Taipei Medical University, Taipei, Taiwan.
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Chiang
authors.affiliation: Department of Pharmacy, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; School of Pharmacy, Taipei Medical University, Taipei, Taiwan.
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Kuo
authors.affiliation: Department of Pharmacy, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; School of Pharmacy, Taipei Medical University, Taipei, Taiwan.
authors.forename: Yu-Hsuan
authors.initials: YH
authors.lastname: Yen
authors.affiliation: School of Health Care Administration, Taipei Medical University, Taipei, Taiwan.
authors.forename: Chao-Hsiun
authors.initials: CH
authors.lastname: Tang
authors.affiliation: Department of Pharmacy, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; School of Pharmacy, Taipei Medical University, Taipei, Taiwan. Electronic address: shawn@tmu.edu.tw.
authors.forename: Hsiang-Yin
authors.initials: HY
authors.lastname: Chen
mesh_terms: D000068879:Adalimumab; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000453:epidemiology*; D001424:Bacterial Infections / Q000175:diagnosis / Q000453:epidemiology*; D015984:Causality; D015897:Comorbidity; D018572:Disease-Free Survival; D000068800:Etanercept; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000627:therapeutic use*; D015994:Incidence; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D018124:Receptors, Tumor Necrosis Factor / Q000627:therapeutic use*; D012307:Risk Factors; D017678:Sex Distribution; D013624:Taiwan / Q000453:epidemiology; D016896:Treatment Outcome
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D018501:Antirheumatic Agents; D007074:Immunoglobulin G; D047908:Intracellular Signaling Peptides and Proteins; D018124:Receptors, Tumor Necrosis Factor; C000593651:TNFAIP8L3 protein, human; D000068879:Adalimumab; D000068800:Etanercept
keywords: Adalimumab; Etanercept; Infection; Rheumatoid arthritis; Tumor necrosis factor-α antagonist