title: The International Study of Wheezing in Infants: questionnaire validation.
abstract: BACKGROUND
  There are no internationally validated questionnaires to investigate the prevalence of infant wheezing. This study was undertaken to validate a questionnaire for the International Study on the Prevalence of Wheezing in Infants (Estudio Internacional de Sibilancias en Lactantes, EISL).
  
  
  METHODS
  Construct and criterion validity were tested for the question 'Has your baby had wheezing or whistling in the chest during his/her first 12 months of life?'. Construct validity (i.e. the ability of parents and doctors to refer to the same symptoms with the same words) was tested in a sample of 50 wheezing and 50 non-wheezy infants 12-15 months of age in each of 10 centres from 6 different Spanish- or Portuguese-speaking countries. Criterion validity (i.e. the ability of parents to correctly detect the symptom in the general population) was evaluated in 2 samples (Santiago, Chile and Cartagena, Spain) of 50 wheezing and 50 non-wheezing infants (according to parents) of the same age, randomly selected from the general population, who were later blindly diagnosed by a paediatric pulmonologist.
  
  
  RESULTS
  Construct validity was very high (kappa test: 0.98-1) in all centres. According to Youden's index, criterion validity was good both in Cartagena (75.5%) and in Santiago (67.0%). Adding questions about asthma medication did not improve diagnosis accuracy.
  
  
  CONCLUSIONS
  The EISL questionnaire significantly distinguished wheezy infants from healthy ones. This questionnaire has a strong validity and can be employed in large international multicentre studies on wheezing during infancy.
authors.affiliation: Department of Paediatric Respiratory Medicine, Hospital El Pino, University of Santiago de Chile, Santiago de Chile, Chile. jmallol@usach.cl
authors.forename: Javier
authors.initials: J
authors.lastname: Mallol
authors.forename: Luis
authors.initials: L
authors.lastname: García-Marcos
authors.forename: Viviana
authors.initials: V
authors.lastname: Aguirre
authors.forename: Antonela
authors.initials: A
authors.lastname: Martinez-Torres
authors.forename: Virginia
authors.initials: V
authors.lastname: Perez-Fernández
authors.forename: Alejandro
authors.initials: A
authors.lastname: Gallardo
authors.forename: Mario
authors.initials: M
authors.lastname: Calvo
authors.forename: Nelson
authors.initials: N
authors.lastname: Rosario Filho
authors.forename: Wilson
authors.initials: W
authors.lastname: Rocha
authors.forename: Gilberto
authors.initials: G
authors.lastname: Fischer
authors.forename: Manuel
authors.initials: M
authors.lastname: Baeza-Bacab
authors.forename: Pascual
authors.initials: P
authors.lastname: Chiarella
authors.forename: Rosario
authors.initials: R
authors.lastname: Pinto
authors.forename: Claudio
authors.initials: C
authors.lastname: Barria
mesh_terms: D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D006801:Humans; D007223:Infant; D007843:Latin America; D010290:Parents; D010820:Physicians; D015995:Prevalence; D012008:Recurrence; D012135:Respiratory Sounds / Q000175:diagnosis* / Q000276:immunology*; D013030:Spain; D011795:Surveys and Questionnaires