title: Importance of attributable risk in monitoring adverse events after immunization: hepatitis B vaccination in children.
abstract: OBJECTIVE
  Most vaccine safety data present only the postvaccination incidence of all adverse events rather than an estimate of attributable risk. This study sought to illustrate the difference between the 2 estimates with data from a hepatitis B immunization program.
  
  
  METHODS
  The incidence of health problems occurring before and after each dose of hepatitis B vaccine in a cohort of 1130 children were compared.
  
  
  RESULTS
  Although 47.5% of all children reported an adverse event during the 4 weeks following each of the 3 doses, adverse events attributable to immunization occurred in only 10.6% of children.
  
  
  CONCLUSIONS
  Postimmunization incidence systematically overestimates the risk of adverse events. Estimating actual attributable risk is necessary to avoid false beliefs regarding immunization.
authors.affiliation: Institut national de santé publique du Québec, Québec Canada. gdeserres@cspq.qc.ca
authors.forename: G
authors.initials: G
authors.lastname: De Serres
authors.forename: B
authors.initials: B
authors.lastname: Duval
authors.forename: N
authors.initials: N
authors.lastname: Boulianne
authors.forename: M
authors.initials: M
authors.lastname: Rochette
authors.forename: M
authors.initials: M
authors.lastname: Dionne
authors.forename: M D
authors.initials: MD
authors.lastname: Fradet
authors.forename: R
authors.initials: R
authors.lastname: Massé
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D015982:Bias; D002648:Child; D003627:Data Interpretation, Statistical; D004342:Drug Hypersensitivity / Q000453:epidemiology / Q000209:etiology; D016903:Drug Monitoring / Q000379:methods*; D005334:Fever / Q000139:chemically induced / Q000453:epidemiology; D005500:Follow-Up Studies; D005767:Gastrointestinal Diseases / Q000139:chemically induced / Q000453:epidemiology; D006261:Headache / Q000139:chemically induced / Q000453:epidemiology; D017325:Hepatitis B Vaccines / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D011792:Quebec / Q000453:epidemiology; D012140:Respiratory Tract Diseases / Q000139:chemically induced / Q000453:epidemiology; D012307:Risk Factors; D014504:Urban Health / Q000706:statistics & numerical data; D014614:Vaccines, Synthetic / Q000009:adverse effects*
chemical_list: C075654:Engerix-B; D017325:Hepatitis B Vaccines; D014614:Vaccines, Synthetic