title: Development of Danish version of child oral-health-related quality of life questionnaires (CPQ8-10 and CPQ11-14).
abstract: BACKGROUND
  The Child Perceptions Questionnaire (CPQ) is a self-reported questionnaire developed to measure oral health-related quality of life in children. The CPQ aims to improve the description of children's oral health, while taking into consideration the importance of psychological aspects in the concept of health. The CPQ exists in two versions: the CPQ8-10 for children aged 8-10 years and the CPQ11-14 for those aged 11-14 years. The aim of this study was to develop a Danish version of the CPQ8-10 and the CPQ11-14 and to evaluate its validity for use among Danish-speaking children.
  
  
  METHODS
  The instruments were translated from English into Danish in accordance with a recommended translation procedure. Afterwards, they were tested among children aged 8-10 (n = 120) and 11-14 years (n = 225). The validity was expressed by the correlation between overall CPQ scores and i) self-reported assessment of the influence of oral conditions on everyday life (not at all, very little, some, a lot, very much) and ii) the self-reported rating of oral health. Furthermore, groups of children with assumed decreased oral health-related quality of life were compared with children with healthy oral conditions. Finally, we examined the internal consistency.
  
  
  RESULTS
  The correlation between overall CPQ scores and global assessments of the influence of oral conditions on everyday life showed Spearman correlation coefficients of 0.45, P < 0.001 for CPQ8-10 and 0.50, P < 0.001 for CPQ11-14. The correlation between overall CPQ scores and the self-reported rating of oral health showed Spearman correlation coefficients of 0.45, P < 0.001 for CPQ8-10 and 0.17, P = 0.010 for CPQ11-14.The median overall CPQ8-10 scores were 7 for individuals with healthy oral conditions, 5 for individuals with cleft lip and palate, and 15 for individuals with rare oral diseases. The median overall CPQ11-14 scores were 9 for individuals with healthy oral conditions, 9 for individuals with cleft lip and palate, 17.0 for individuals with rare oral diseases, and 22.0 for individuals with fixed orthodontic appliances. There were statistically significant differences between the groups of children with healthy oral conditions and each of the subgroups, except for children with cleft lip and palate.Chronbach'alpha were 0.82 for CPQ8-10 and 0.87 for CPQ11-14.
  
  
  CONCLUSIONS
  The results of this study reveal that the Danish CPQ8-10 and CPQ11-14, seem to be valid instruments for measuring oral health-related quality of life in children although its ability to discriminate between children with cleft lip and palate and healthy children seem to be limited.
authors.affiliation: Department of Paediatric Dentistry, School of Dentistry, Faculty of Health Sciences, Aarhus University, Vennelyst Boulevard 9, DK-8000 Aarhus, Denmark. wog-fb@aalborg.dk
authors.forename: Pia
authors.initials: P
authors.lastname: Wogelius
authors.forename: Hans
authors.initials: H
authors.lastname: Gjørup
authors.forename: Dorte
authors.initials: D
authors.lastname: Haubek
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Lopez
authors.forename: Sven
authors.initials: S
authors.lastname: Poulsen