title: "Attacks" or "Whistling": Impact of Questionnaire Wording on Wheeze Prevalence Estimates.
abstract: BACKGROUND
  Estimates of prevalence of wheeze depend on questionnaires. However, wording of questions may vary between studies. We investigated effects of alternative wording on estimates of prevalence and severity of wheeze, and associations with risk factors.
  
  
  METHODS
  White and South Asian children from a population-based cohort (UK) were randomly assigned to two groups and followed up at one, four and six years (1998, 2001, 2003). Parents were asked either if their child ever had "attacks of wheeze" (attack group, N=535), or "wheezing or whistling in the chest" (whistling group, N=2859). All other study aspects were identical, including questions about other respiratory symptoms.
  
  
  RESULTS
  Prevalence of wheeze ever was lower in the attack group than in the whistling group for all surveys (32 vs. 40% in white children aged one year, p<0.001). Prevalence of other respiratory symptoms did not differ between groups. Wheeze tended to be more severe in the attack group. The strength of association with risk factors was comparable in the two groups.
  
  
  CONCLUSIONS
  The wording of questions on wheeze can affect estimates of prevalence, but has less impact on measured associations with risk factors. Question wording is a potential source of between-study-heterogeneity in meta-analyses.
authors.affiliation: Institute of Social and Preventive Medicine, University Bern, Bern, Switzerland.
authors.forename: Anina M
authors.initials: AM
authors.lastname: Pescatore
authors.affiliation: Institute of Social and Preventive Medicine, University Bern, Bern, Switzerland.
authors.forename: Ben D
authors.initials: BD
authors.lastname: Spycher
authors.affiliation: Division of Child Health, Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom.
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Beardsmore
authors.affiliation: Institute of Social and Preventive Medicine, University Bern, Bern, Switzerland.
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Kuehni
mesh_terms: D001249:Asthma / Q000453:epidemiology; D002675:Child, Preschool; D015331:Cohort Studies; D003144:Communication Barriers; D004417:Dyspnea / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007802:Language; D008297:Male; D010290:Parents; D010465:Perception; D015995:Prevalence; D012135:Respiratory Sounds / Q000175:diagnosis*; D012720:Severity of Illness Index; D063346:Singing; D011795:Surveys and Questionnaires / Q000592:standards*