title: Bed-sharing and risk of hospitalisation due to pneumonia and diarrhoea in infancy: the 2004 Pelotas Birth Cohort.
abstract: OBJECTIVE
  To investigate the association between bed-sharing with the mother at 3 months of age and incidence of hospitalisation due to pneumonia and diarrhoea between 3 and 12 months.
  
  
  METHODS
  The 2004 Pelotas Birth Cohort included all live births to mothers living in Pelotas, Brazil, in 2004. Information on bed-sharing was obtained at the 3-month follow-up visit, and on hospitalisations at the 12-month visit, both based on mothers' reports. Only singleton infants with complete information on hospitalisation were analysed.
  
  
  RESULTS
  3906 infants were included. The bed-sharing prevalence at 3 months was 46.4% (95% CI 44.9 to 48.0%). The incidence of pneumonia admissions between 3 and 12 months was 3.6% (95% CI 3.3 to 4.2%) and diarrhoea, 0.9% (95% CI 0.6 to 1.2%). In crude analyses, bed-sharing with the mother was associated with higher incidence of hospitalisation due to both pneumonia and diarrhoea. There was interaction between bed-sharing and duration of breastfeeding regarding the chance of admission due to pneumonia. Among infants breastfed for 3 months or less, the chance of hospitalisation due to pneumonia among bed-sharers was almost twice as high as among non-bed-sharers (adjusted OR 1.96; 95% CI 1.08 to 3.55). There was no association between bed-sharing and hospitalisation due to pneumonia among infants breastfed for longer than 3 months in crude or adjusted analyses. The association between bed-sharing and admissions due to diarrhoea lost statistical significance after allowing for confounders.
  
  
  CONCLUSIONS
  The effect of bed-sharing in infancy on the risk of hospitalisation due to pneumonia depends on breastfeeding, such that weaned children present higher risk.
authors.affiliation: Postgraduate Epidemiology Program, Federal University of Pelotas, Pelotas, RS, Brazil.
authors.forename: Kátia M A
authors.initials: KM
authors.lastname: Ngale
authors.forename: Iná S
authors.initials: IS
authors.lastname: Santos
authors.forename: David A
authors.initials: DA
authors.lastname: González-Chica
authors.forename: Aluísio J D
authors.initials: AJ
authors.lastname: de Barros
authors.forename: Alicia
authors.initials: A
authors.lastname: Matijasevich
mesh_terms: D000328:Adult; D001512:Bedding and Linens; D001723:Birth Rate; D001938:Brazil / Q000453:epidemiology; D001942:Breast Feeding / Q000379:methods / Q000523:psychology / Q000706:statistics & numerical data; D015331:Cohort Studies; D003441:Crowding; D003967:Diarrhea / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007224:Infant Care / Q000379:methods / Q000592:standards; D011014:Pneumonia / Q000453:epidemiology* / Q000209:etiology; D015995:Prevalence; D012307:Risk Factors; D012890:Sleep; D012959:Socioeconomic Factors