The concept of validity in sociodental indicators and oral health-related quality-of-life measures

Background: Most of the psychometric instruments used to measure quality of life associated with oral impairment and disability from the perspectives of older adults focus on negative experiences, and pay little attention to the possibility of positive reactions to disablement. This oversight challenges the validity of the instruments in current use, and raises questions about the process used to validate them. Objectives: In this study, we consider the general attributes of psychometric validity, and how they have been applied to oral health-related instruments. Conclusions and recommendations: The psychometric characteristics and predictive validity of existing dental instruments are still weak, probably because the instruments fail to address the broad range of personal variables that influence oral health, disability and quality of life. We recommend, therefore, that a continuous process of validation be adopted to include: (1) assessments of the theoretical framework supporting the instruments; (2) evaluations of the focus and structure of the questions used; and (3) enhancements of the prediction value of instruments applicable to oral health-related beliefs and behaviours.