Development of a child-centred, caries-specific measure of oral health-related quality of life

Background: Existing oral health-related quality of life (OHRQoL) measures are generic and have not involved children at all stages of development. Aim: To develop a caries-specific measure of OHRQoL for children. Design: The first phase involved a systematic review of the three most commonly used child self-report measures of OHRQoL. This was followed by a qualitative study with children, aged 5-16 years, to develop the measure and, finally, a cross-sectional validation study. Necessary ethical approval was granted for the study. Results: The systematic review included 120 papers and revealed that the three most commonly used existing measures had included children only in the latter stages of development. There was lack of testing for unidimensionality, although other properties were satisfactory. The qualitative study found that children discussed a number of caries-related impacts which affected their daily lives. These were incorporated into a draft measure which was further refined following testing of face and content validity. The questionnaire for validity testing contained 16 items and one global question and was named the Caries Impacts and Experiences Questionnaire for Children (CARIES-QC). Two hundred participants with a mean (range) age of 8.1 (5-16) years took part in the evaluation of CARIES-QC. Four items, which did not fit the Rasch model, were removed from further analysis. The remaining 12 items demonstrated good internal consistency (alpha=0.9) and the total score showed significant correlations with the number of decayed teeth, presence of pain, pulpal involvement, the Child Perceptions Questionnaire (16-item short form) and the global score (p<0.01, Spearman’s rho). Conclusion: CARIES-QC demonstrates acceptable validity, reliability and responsiveness using both modern psychometric techniques and Classical Test Theory. Its unidimensionality allows the transformation of raw scores, enabling accurate calculation of effect sizes and change scores following treatment of dental caries.