title: Validation of the GerdQ questionnaire for the management of gastro-oesophageal reflux disease in Japan.
abstract: BACKGROUND
  The GerdQ scoring system may be a useful tool for managing gastro-oesophageal reflux disease. However, GerdQ has not been fully validated in Asian countries.
  
  
  OBJECTIVE
  To validate the Japanese version of GerdQ and to compare this version to the Carlsson-Dent questionnaire (CDQ) in both general and hospital-based populations.
  
  
  METHODS
  The questionnaires, including the Japanese versions of GerdQ and CDQ, and questions designed to collect demographic information, were sent to a general population via the web, and to a hospital-based population via conventional mail. The optimal cutoff GerdQ score and the differences in the characteristics between GerdQ and CDQ were assessed.
  
  
  RESULTS
  The answers from 863 web-responders and 303 conventional-mail responders were analysed. When a GerdQ cutoff score was set at 8, GerdQ significantly predicted the presence of reflux oesophagitis. Although the GerdQ scores were correlated with the CDQ scores, the concordance rates were poor. Multivariate analysis results indicated that, the additional use of over-the-counter medications was associated with GerdQ score ≥ 8, but not with CDQ score ≥ 6.
  
  
  CONCLUSIONS
  The GerdQ cutoff score of 8 was appropriate for the Japanese population. Compared with CDQ, GerdQ was more useful for evaluating treatment efficacy and detecting patients' unmet medical needs.
authors.affiliation: Keio University School of Medicine, Tokyo, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Keio University School of Medicine, Tokyo, Japan.
authors.forename: Juntaro
authors.initials: J
authors.lastname: Matsuzaki
authors.affiliation: Keio University School of Medicine, Tokyo, Japan.
authors.forename: Sawako
authors.initials: S
authors.lastname: Okada
authors.affiliation: Keio University School of Medicine, Tokyo, Japan.
authors.forename: Kenro
authors.initials: K
authors.lastname: Hirata
authors.affiliation: Keio University School of Medicine, Tokyo, Japan.
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Fukuhara
authors.affiliation: Keio University School of Medicine, Tokyo, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Hibi
keywords: Cutoff; GERD; GerdQ; questionnaire; unmet medical need