title: The transient value of classifying preschool wheeze into episodic viral wheeze and multiple trigger wheeze.
abstract: BACKGROUND
  A recently proposed method for classifying preschool wheeze is to describe it as either episodic (viral) wheeze or multiple trigger wheeze. In research studies, phenotype is generally determined by retrospective questionnaire.
  
  
  OBJECTIVE
  To determine whether recently proposed phenotypes of preschool wheeze are stable over time.
  
  
  METHODS
  In all, 132 two to six-year-old children with doctor diagnosed asthma on maintenance inhaled corticosteroids were classified as having episodic (viral) wheeze or multiple trigger wheeze at a screening visit and then followed up at three-monthly intervals for a year. At each follow-up visit, standardized questionnaires were used to determine whether the subjects wheezed only with, or also in the absence of colds. Stability of the phenotypes was assessed at the end of the study.
  
  
  RESULTS
  Phenotype as determined by retrospective parental report at the start of the study was not predictive of phenotype during the study year. Phenotypic classification remained the same in 45.9% of children and altered in 54.1% of children.
  
  
  CONCLUSIONS
  When children with preschool wheeze are classified into episodic (viral) wheeze or multiple trigger wheeze based on retrospective questionnaire, the classification is likely to change significantly within a 1-year period.
authors.affiliation: School of Paediatric and Child Health, University of Western Australia, Perth, WA, Australia. andre.schultz@health.wa.gov.au
authors.forename: A
authors.initials: A
authors.lastname: Schultz
authors.forename: S G
authors.initials: SG
authors.lastname: Devadason
authors.forename: O E M
authors.initials: OE
authors.lastname: Savenije
authors.forename: P D
authors.initials: PD
authors.lastname: Sly
authors.forename: P N
authors.initials: PN
authors.lastname: Le Souëf
authors.forename: P L P
authors.initials: PL
authors.lastname: Brand
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D001249:Asthma / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D010641:Phenotype; D011446:Prospective Studies; D012135:Respiratory Sounds / Q000145:classification* / Q000209:etiology; D012141:Respiratory Tract Infections / Q000150:complications* / Q000175:diagnosis; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D014777:Virus Diseases / Q000150:complications* / Q000175:diagnosis
chemical_list: D000305:Adrenal Cortex Hormones