title: Early detection and counselling intervention of asthma symptoms in preschool children: study design of a cluster randomised controlled trial.
abstract: BACKGROUND
  Prevention of childhood asthma is an important public health objective. This study evaluates the effectiveness of early detection of preschool children with asthma symptoms, followed by a counselling intervention at preventive child health centres. Early detection and counselling is expected to reduce the prevalence of asthma symptoms and improve health-related quality of life at age 6 years.
  
  
  METHODS
  This cluster randomised controlled trial was embedded within the Rotterdam population-based prospective cohort study Generation R in which 7893 children (born between April 2002 and January 2006) participated in the postnatal phase. Sixteen child health centres are involved, randomised into 8 intervention and 8 control centres. Since June 2005, an early detection tool has been applied at age 14, 24, 36 and 45 months at the intervention centres. Children who met the intervention criteria received counselling intervention (personal advice to parents to prevent smoke exposure of the child, and/or referral to the general practitioner or asthma nurse). The primary outcome was asthma diagnosis at age 6 years. Secondary outcomes included frequency and severity of asthma symptoms, health-related quality of life, fractional exhaled nitric oxide and airway resistance at age 6 years. Analysis was according to the intention-to-treat principle. Data collection will be completed end 2011.
  
  
  CONCLUSIONS
  This study among preschool children provides insight into the effectiveness of early detection of asthma symptoms followed by a counselling intervention at preventive child health centres.
  
  
  BACKGROUND
  Current Controlled Trials ISRCTN15790308.
authors.affiliation: The Generation R Study Group, Erasmus MC, Rotterdam, The Netherlands. e.hafkamp@erasmusmc.nl
authors.forename: Esther
authors.initials: E
authors.lastname: Hafkamp-de Groen
authors.forename: Ashna D
authors.initials: AD
authors.lastname: Mohangoo
authors.forename: Johan C
authors.initials: JC
authors.lastname: de Jongste
authors.forename: Johannes C
authors.initials: JC
authors.lastname: van der Wouden
authors.forename: Henriëtte A
authors.initials: HA
authors.lastname: Moll
authors.forename: Vincent Wv
authors.initials: VW
authors.lastname: Jaddoe
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.forename: Harry J
authors.initials: HJ
authors.lastname: de Koning
authors.forename: Hein
authors.initials: H
authors.lastname: Raat
mesh_terms: D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology; D002675:Child, Preschool; D016000:Cluster Analysis; D003376:Counseling; D042241:Early Diagnosis; D006801:Humans; D007223:Infant; D009426:Netherlands; D011795:Surveys and Questionnaires