title: Increased risk of childhood asthma from antibiotic use in early life.
abstract: BACKGROUND
  To address the major methodological issues of reverse causation and selection bias in epidemiologic studies of antibiotic use in early life and the development of asthma, we undertook a cohort study of this association in a complete population of children.
  
  
  METHODS
  Using the health-care and prescription databases of Manitoba, Canada, this longitudinal study assessed the association between antibiotic prescription use during the first year of life and asthma at age 7 years in a 1995 birth cohort of 13,116 children.
  
  
  RESULTS
  Independent of well-known asthma risk factors, asthma was significantly more likely to develop in children who had received antibiotics in the first year of life at age 7 years. The association with asthma was observed for antibiotic use in non-respiratory tract infections (adjusted odds ratio [OR], 1.86; 95% confidence interval [CI], 1.02 to 3.37). The risk of asthma was highest in children receiving more than four courses of antibiotics (adjusted OR, 1.46; 95% CI, 1.14 to 1.88), especially among rural children, and in the absence of maternal asthma or a dog in the birth year. Broad-spectrum (BS) cephalosporin use was more common in these subpopulations of children.
  
  
  CONCLUSIONS
  Antibiotic use in early life was associated with the development of childhood asthma, a risk that may be reduced by avoiding the use of BS cephalosporins.
authors.affiliation: Faculty of Pharmacy, University of Manitoba, Winnipeg, MB, Canada R3T 2N2. kozyrsk@cc.umanitoba.ca
authors.forename: Anita L
authors.initials: AL
authors.lastname: Kozyrskyj
authors.forename: Pierre
authors.initials: P
authors.lastname: Ernst
authors.forename: Allan B
authors.initials: AB
authors.lastname: Becker
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001249:Asthma / Q000453:epidemiology*; D002511:Cephalosporins / Q000627:therapeutic use*; D002648:Child; D015331:Cohort Studies; D004342:Drug Hypersensitivity / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007229:Infant Welfare; D008137:Longitudinal Studies; D008297:Male; D008350:Manitoba / Q000453:epidemiology; D016017:Odds Ratio; D012141:Respiratory Tract Infections / Q000188:drug therapy; D012307:Risk Factors
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins