title: Synthetic bedding and wheeze in childhood.
abstract: BACKGROUND
  The reasons for the increase in childhood asthma over time are unclear. The indoor environment is of particular concern. An adverse role for synthetic bedding on asthma development in childhood has been suggested by cross-sectional studies that have found an association between synthetic pillow use and childhood wheeze. Prospective data on infant bedding have not been available.
  
  
  METHODS
  Bedding data at 1 month of age were available from an infant survey for children who were participating in a 1995 follow-up study (N = 863; 78% traced). The 1995 follow-up was embedded in a larger cross-sectional survey involving 6,378 seven year olds in Tasmania (N = 92% of eligible). Outcome measures included respiratory symptoms as defined in the International Study of Asthma and Allergies in Childhood protocol. Frequent wheeze was defined as more than 12 wheeze episodes over the past year compared with no wheeze.
  
  
  RESULTS
  Synthetic pillow use at 1 month of age was associated with frequent wheeze at age 7 (adjusted relative risk [aRR] = 2.5; 95% confidence interval [CI] = 1.2-5.5) independent of childhood exposure. Current synthetic pillow and quilt use was strongly associated with frequent wheeze (aRR = 5.2; CI = 1.3-20.6). Substantial trends were evident for an association of increasing number of synthetic bedding items with frequent wheeze and with increasing wheeze frequency. Among children with asthma, the age of onset of asthma occurred earlier if synthetic bedding was used in infancy.
  
  
  CONCLUSIONS
  In this cohort, synthetic bedding was strongly and consistently associated with frequent childhood wheeze. The association did not appear to be attributable to bedding choice as part of an asthma management strategy.
authors.affiliation: National Centre for Epidemiology and Population Health, Australian National University, Canberra, Australia. anne-louise.ponsonby@anu.edu.au
authors.forename: Anne-Louise
authors.initials: AL
authors.lastname: Ponsonby
authors.forename: Terence
authors.initials: T
authors.lastname: Dwyer
authors.forename: Andrew
authors.initials: A
authors.lastname: Kemp
authors.forename: Jennifer
authors.initials: J
authors.lastname: Cochrane
authors.forename: David
authors.initials: D
authors.lastname: Couper
authors.forename: Allan
authors.initials: A
authors.lastname: Carmichael
mesh_terms: D001249:Asthma / Q000453:epidemiology / Q000209:etiology*; D001512:Bedding and Linens / Q000009:adverse effects*; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D006801:Humans; D007223:Infant; D008420:Manufactured Materials / Q000009:adverse effects; D012135:Respiratory Sounds / Q000209:etiology*; D013648:Tasmania / Q000453:epidemiology