title: Difference in the risk of serious infections in patients with rheumatoid arthritis treated with adalimumab, infliximab and etanercept: results from the Dutch Rheumatoid Arthritis Monitoring (DREAM) registry.
abstract: BACKGROUND
  Tumour necrosis factor (TNF)-inhibiting therapy increases the risk of serious infections in rheumatoid arthritis (RA). However, it is not clear whether this risk differs between TNF inhibitors.
  
  
  OBJECTIVE
  To analyse whether the risk of serious infections in patients with RA treated with an anti-TNF inhibitor is different for adalimumab, infliximab and etanercept.
  
  
  METHODS
  Data from the Dutch RA monitoring registry were used. Incidence rates were calculated from the observed number of first serious infections and follow-up time up to 5 years. A Cox proportional hazards model with time-to-first-serious infection was used to estimate risk differences among the anti-TNF treatment groups, with correction for confounders.
  
  
  RESULTS
  The unadjusted incidence rate of a first serious infection in patients with RA per 100 patient-years was 2.61 (95% CI 2.21 to 3.00) for adalimumab, 3.86 (95% CI 3.33 to 4.40) for infliximab and 1.66 (95% CI 1.09 to 2.23) for etanercept. Age, year of starting anti-TNF therapy, comorbidities at baseline and disease activity score 28 over time were included as confounders. No difference in risk for serious infections was found between adalimumab and infliximab with an adjusted HR (adjHR) of 0.90 (95% CI 0.55 to 1.48). The risk of serious infections was significantly lower in etanercept than in both infliximab (adjHR=0.49 (95% CI 0.29 to 0.83)) and adalimumab (adjHR=0.55 (95% CI 0.44 to 0.67)).
  
  
  CONCLUSIONS
  The risk of serious infections in patients with RA treated with adalimumab or infliximab was similar, while the risk of serious infections in patients with RA treated with etanercept was lower than with both adalimumab and infliximab.
authors.affiliation: Department of Rheumatology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Sanne A A
authors.initials: SA
authors.lastname: van Dartel
authors.forename: Jaap
authors.initials: J
authors.lastname: Fransen
authors.forename: Wietske
authors.initials: W
authors.lastname: Kievit
authors.forename: Marcel
authors.initials: M
authors.lastname: Flendrie
authors.forename: Alfons A
authors.initials: AA
authors.lastname: den Broeder
authors.forename: H
authors.initials: H
authors.lastname: Visser
authors.forename: A
authors.initials: A
authors.lastname: Hartkamp
authors.forename: Mart A F J
authors.initials: MA
authors.lastname: van de Laar
authors.forename: Piet L C M
authors.initials: PL
authors.lastname: van Riel
mesh_terms: D000068879:Adalimumab; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000009:adverse effects*; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects*; D018501:Antirheumatic Agents / Q000009:adverse effects*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D015331:Cohort Studies; D000068800:Etanercept; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000009:adverse effects*; D015994:Incidence; D007239:Infections / Q000453:epidemiology / Q000209:etiology*; D000069285:Infliximab; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018124:Receptors, Tumor Necrosis Factor; D012042:Registries; D012306:Risk; D012720:Severity of Illness Index
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D018501:Antirheumatic Agents; D007074:Immunoglobulin G; D018124:Receptors, Tumor Necrosis Factor; D000069285:Infliximab; D000068879:Adalimumab; D000068800:Etanercept