title: Protective benefit of predominant breastfeeding against otitis media may be limited to early childhood: results from a prospective birth cohort study.
abstract: OBJECTIVE
  To examine the long-term effects of predominant breastfeeding on incidence of otitis media.
  
  
  METHODS
  Prospective birth cohort study.
  
  
  METHODS
  The West Australian Pregnancy Cohort (Raine) Study recruited 2900 mothers through antenatal clinics at the major tertiary obstetric hospital in Perth, Western Australia, between 1989 and 1992.
  
  
  METHODS
  In total, 2237 children participated in a 6-year cohort follow-up, and a subset of 1344 were given ear and hearing assessments.
  
  
  METHODS
  OM diagnosis at 6 years of age (diagnosed by low-compliance tympanograms, 0-0.1 mmho). This was compared to OM diagnosed at the 3-year cohort follow-up using parent-report measures. Main exposure measures were duration of predominant breastfeeding (defined as the age other milk was introduced) and duration of partial (any) breastfeeding (defined as the age breastfeeding was stopped).
  
  
  RESULTS
  There was a significant, independent association between predominant breastfeeding (OR = 1.33 [1.04, 1.69]; P = 0.02) and OM, and breastfeeding duration (OR = 1.35 [1.08, 1.68]; P = 0.01) with OM at 3 years of age. However, at 6 years of age, this relationship was no longer statistically significant (predominant breastfeeding OR = 0.78 [0.48, 1.06]; P = 0.09; duration of breastfeeding, OR = 1.34 [0.81, 2.23]; P = 0.25).
  
  
  CONCLUSIONS
  Our findings are in line with a number of epidemiological studies which show a positive association between breastfeeding and OM in early childhood. However, the long-term follow-up of these children revealed that by 6 years of age, there was no significant influence of breastfeeding on presence of OM. These results suggest that the protective effect of predominant breastfeeding for at least 6 months does not extend to school-age children, where other social and environmental factors may be stronger predictors of OM.
authors.affiliation: Ear Science Institute Australia, Subiaco, WA, Australia.|Ear Sciences Centre, School of Surgery, The University of Western Australia, Crawley, WA, Australia.
authors.forename: C G
authors.initials: CG
authors.lastname: Brennan-Jones
authors.affiliation: Ear Science Institute Australia, Subiaco, WA, Australia.|Ear Sciences Centre, School of Surgery, The University of Western Australia, Crawley, WA, Australia.|Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa.
authors.forename: R H
authors.initials: RH
authors.lastname: Eikelboom
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Crawley, WA, Australia.|School of Population Health, The University of Western Australia, Crawley, WA, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Jacques
authors.affiliation: Ear Science Institute Australia, Subiaco, WA, Australia.|Ear Sciences Centre, School of Surgery, The University of Western Australia, Crawley, WA, Australia.|Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa.
authors.forename: D
authors.initials: D
authors.lastname: Swanepoel
authors.affiliation: Ear Science Institute Australia, Subiaco, WA, Australia.|Ear Sciences Centre, School of Surgery, The University of Western Australia, Crawley, WA, Australia.
authors.forename: M D
authors.initials: MD
authors.lastname: Atlas
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Crawley, WA, Australia.
authors.forename: A J O
authors.initials: AJ
authors.lastname: Whitehouse
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Crawley, WA, Australia.
authors.forename: S E
authors.initials: SE
authors.lastname: Jamieson
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Crawley, WA, Australia.
authors.forename: W H
authors.initials: WH
authors.lastname: Oddy
mesh_terms: D000367:Age Factors; D001315:Australia; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010033:Otitis Media / Q000453:epidemiology* / Q000517:prevention & control; D012959:Socioeconomic Factors; D013997:Time Factors