Objective: To determine whether or not self-weighting at an item level contributes to the performance of an oral health-related quality-of-life measure.
Design: Data were collected in two national surveys conducted a month apart, one using the "weighted" measure and the other an "unweighted" version of the UK oral health-related quality-of-life measure. In addition, sociodemographic and self-reported oral health status were recorded.
Results: The UK oral health-related quality-of-life measure discriminated between groups based on age group (<65, 65 and older) and social class (higher and lower) irrespective of the version of the questionnaire used. Both versions also showed significant associations with self-reported oral health: denture status (P < 0.01) and number of teeth possessed (P < 0.01). In addition, both versions demonstrated predictive ability in identifying those in prosthetic need (<20 teeth and without recourse to a denture, P < 0.01).
Conclusion: Weighting the UK oral health-related quality-of-life instrument does not improve the psychometric properties of the instrument and thus raises questions about the value of self-weighting at an item level.
Copyright Blackwell Munksgaard, 2004