Validation of a 4-item child perception questionnaire in Australian children

OBJECTIVE: To develop and validate a 4-item child oral health-related quality of life (OHRQoL) instrument that might be more amenable for uptake in large scale, multifaceted surveys of children’s health and wellbeing than current, longer-form child OHRQoL instruments. METHODS: Data were obtained from a study of the South Australian School Dental Service population designed to investigate OHRQoL among school children aged 8–13 years in 2002–2003. The Child Perception Questionnaire (CPQ(8-10) and CPQ(11-14)) was utilised, which comprises 25 & 37 items representing four conceptual domains: oral symptoms, functional limitations, emotional wellbeing and social wellbeing. Initially, the psychometric properties of the short form 8-item CPQ were tested in both age groups using Confirmatory Factor Analysis. The rationale was that, if the 8-item CPQ(8-10) and CPQ(11-14) did not display good psychometric properties, there was no reason to proceed with further shortening into 4-item versions. Following a good fit of the 8-item CPQ, items with higher factor loadings in each domain were maintained and tested in the development of a 4-item CPQ. Exploratory Factor Analysis was conducted to determine dimensionality, followed by tests for reliability and validity. Model fits were assessed using Root Mean Square Error of Approximation (RMSEA), Comparative Fit Index (CFI) and Standardized Root Mean Square Residual (SRMR). RESULTS: There were 308 children aged 8–10 years who completed CPQ(8-10) and 461 children aged 11–13 years who completed CPQ(11-14). For the short-form 8-item instrument, satisfactory goodness of fit was demonstrated for the two age groups, with acceptable thresholds for RMSEA, CFI, and SRMR. The four items with the highest factor loading in each domain were the same for the 8-item CPQ(8-10) and CPQ(11-14.) and these items were selected to comprise the 4-item CPQ(8-10) and CPQ(11-14.) The 4-item short form displayed good criterion validity, with expected score patterns found in the majority of the known groups evaluated. CONCLUSIONS: We developed short-form 4-item CPQ(8-10) and CPQ(11-14) instruments that were tested in a large convenience sample of South Australian school children. The instruments demonstrated acceptable reliability and validity. Implications for practice are discussed.