title: Time-dependent variation in the responses to the web-based ISAAC questionnaire.
abstract: BACKGROUND
  Epidemiologic studies have shown seasonal variations in responses to the written questionnaire for rhinitis symptoms.
  
  
  OBJECTIVE
  To evaluate whether the timing of data collection affected responses to the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire in a Web-based study.
  
  
  METHODS
  The Web-based ISAAC questionnaires were completed by parents with children 6 to 12 years old using an online research system. The authors conducted surveys of asthma symptoms every month for 1 year and surveys of rhinitis and eczema symptoms every season throughout 1 entire year.
  
  
  RESULTS
  There was a significant fluctuation in the positive responses to questions about wheezing in the past 12 months (P < .001) but not in the positive responses to questions about exercise-induced wheezing in the past 12 months and asthma ever (P = .75 and P = .15, respectively). The positive responses to questions about rhinitis and allergic rhinoconjunctivitis in the past 12 months and pollinosis ever exhibited significant seasonal variations (P = .002, P < .001, and P < .001, respectively). In contrast, there were no significant variations in positive responses regarding eczema in the past 12 months and eczema ever (P = .33 and P = .55, respectively).
  
  
  CONCLUSIONS
  There were time-dependent fluctuations in responses to the Web-based questionnaire regarding allergic symptoms. Timing of data collection should be taken into account when evaluating prevalence of asthma and rhinitis in children.
authors.affiliation: Division of Allergy, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan. Electronic address: kouichi_yoshida@tmhp.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Pediatrics, University of Toyama, Toyama, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Adachi
authors.affiliation: Division of Allergy, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Sasaki
authors.affiliation: Division of Allergy, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Furukawa
authors.affiliation: Department of Pediatrics, University of Toyama, Toyama, Japan.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Itazawa
authors.affiliation: Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Hashimoto
authors.affiliation: Department of Pediatrics, Fukuoka National Hospital, Fukuoka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Odajima
authors.affiliation: Division of Allergy, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Akasawa
mesh_terms: D001249:Asthma / Q000453:epidemiology*; D016009:Chi-Square Distribution; D002648:Child; D004485:Eczema / Q000453:epidemiology*; D005260:Female; D006801:Humans; D020407:Internet; D007564:Japan; D008297:Male; D010290:Parents; D015995:Prevalence; D012220:Rhinitis / Q000453:epidemiology*; D012621:Seasons; D011795:Surveys and Questionnaires