title: Observational studies of infections in rheumatoid arthritis: a metaanalysis of tumor necrosis factor antagonists.
abstract: OBJECTIVE
  Published metaanalyses of tumor necrosis factor (TNF) antagonists and infection have focused on randomized controlled trials, which tend to have short duration, relatively small size, and stringent inclusion/exclusion criteria that may limit enrollment to patients at low risk of infection. We performed a systematic review and synthesis of observational studies of TNF antagonists and infection risk.
  
  
  METHODS
  We conducted a systematic literature search of studies estimating overall risk of serious infection after anti-TNF exposure in rheumatoid arthritis (RA). We estimated a pooled relative risk (RR) for the relevant observational studies, using a random-effects model.
  
  
  RESULTS
  Five cohort studies and 2 nested case-control studies were included in the metaanalysis. Anti-TNF therapy appeared to significantly increase risk of serious infection (pooled adjusted RR 1.37, 95% CI 1.18, 1.60).
  
  
  CONCLUSIONS
  Our metaanalysis of observational data demonstrated an increased risk of serious infection in subjects with RA receiving anti-TNF therapy, versus those not receiving these agents.
authors.affiliation: Division of Clinical Epidemiology, Department of Medicine, and the Research Institute, McGill University Health Centre, Montreal, Quebec, Canada. sasha.bernatsky@mail.mcgill.ca
authors.forename: Sasha
authors.initials: S
authors.lastname: Bernatsky
authors.forename: Youssef
authors.initials: Y
authors.lastname: Habel
authors.forename: Elham
authors.initials: E
authors.lastname: Rahme
mesh_terms: D000911:Antibodies, Monoclonal / Q000009:adverse effects*; D018501:Antirheumatic Agents / Q000009:adverse effects; D001172:Arthritis, Rheumatoid / Q000628:therapy*; D015331:Cohort Studies; D006801:Humans; D007239:Infections / Q000139:chemically induced*; D016032:Randomized Controlled Trials as Topic; D012306:Risk; D012307:Risk Factors; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D000911:Antibodies, Monoclonal; D018501:Antirheumatic Agents; D014409:Tumor Necrosis Factor-alpha