title: Association of duration of television viewing in early childhood with the subsequent development of asthma.
abstract: OBJECTIVE
  To investigate whether duration of television (TV) viewing in young children is associated with subsequent development of asthma.
  
  
  METHODS
  Children taking part in the Avon Longitudinal Study of Parents and Children (ALSPAC) with no wheeze up to the age of 3.5 years and follow-up data at 11.5 years of age took part in a prospective longitudinal cohort study. The main outcome measure was asthma, defined as doctor-diagnosed asthma by 7.5 years of age with symptoms and/or treatment in the previous 12 months at 11.5 years of age. Parental report of hours of TV viewing per day by the children was ascertained at 39 months.
  
  
  RESULTS
  In children with no symptoms of wheeze at 3.5 years of age and follow-up data at 11.5 years of age, the prevalence of asthma was 6% (185/3065). Increased TV viewing at 3.5 years was associated with increased prevalence of asthma at 11.5 years of age (p for linear trend = 0.0003). Children who watched television for >2 h/day were almost twice as likely to develop asthma by 11.5 years of age as those watching TV for 1-2 h/day (adjusted odds ratio 1.8 (95% CI 1.2 to 2.6)).
  
  
  CONCLUSIONS
  Longer duration of TV viewing in children with no symptoms of wheeze at 3.5 years of age was associated with the development of asthma in later childhood.
authors.affiliation: Dental School, Faculty of Medicine, University of Glasgow, Glasgow G2 3JZ, UK. a.sherriff@dental.gla.ac.uk
authors.forename: A
authors.initials: A
authors.lastname: Sherriff
authors.forename: A
authors.initials: A
authors.lastname: Maitra
authors.forename: A R
authors.initials: AR
authors.lastname: Ness
authors.forename: C
authors.initials: C
authors.lastname: Mattocks
authors.forename: C
authors.initials: C
authors.lastname: Riddoch
authors.forename: J J
authors.initials: JJ
authors.lastname: Reilly
authors.forename: J Y
authors.initials: JY
authors.lastname: Paton
authors.forename: A J
authors.initials: AJ
authors.lastname: Henderson
mesh_terms: D001249:Asthma / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D004739:England / Q000453:epidemiology; D015444:Exercise / Q000502:physiology; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D017678:Sex Distribution; D013690:Television / Q000706:statistics & numerical data*; D013997:Time Factors