Psychometric validation of a novel instrument to measure caregiver-reported oral health-related quality of life in children with intellectual disabilities.

Abstract

Background: Oral health-related quality of life (OHRQoL) is a critical yet underexplored dimension of well-being in children with intellectual disabilities, who experience a disproportionately high burden of oral diseases due to cognitive, behavioural, and self-care limitations. Existing paediatric OHRQoL instruments were developed for typically developing populations and may not capture the unique experiences of this group. This study aimed to evaluate the construct validity, criterion validity, and reliability of a newly developed caregiver-reported OHRQoL instrument specifically designed for children with intellectual disabilities.

Methods: A psychometric validation study was conducted among 200 children aged 12 to 18 years with mild to moderate intellectual disabilities and their mothers/caregivers from four special schools in Pondicherry, India. Caregiver-reported OHRQoL assessments were obtained through structured interviews, and clinical oral examinations recorded caries status. Construct validity was examined using exploratory factor analysis. Criterion, convergent, and discriminant validity were assessed using correlation and group comparison analyses. Reliability was evaluated through Cronbach's alpha, split-half reliability, and test-retest Intraclass Correlation Coefficients. Floor and ceiling effects were examined to determine score distribution.

Results: Exploratory factor analysis yielded a seven-component structure reflecting cognitive, behavioural, emotional, caregiver, health-care system, motor, and family domains. Criterion validity was supported by significant correlations between caregiver-reported OHRQoL scores, perceived oral health, and caries burden. Discriminant validity showed significantly poorer caregiver-reported OHRQoL among children with higher caries experience. The instrument demonstrated excellent internal consistency (overall α = 0.947), strong split-half reliability, and acceptable test-retest stability. No ceiling effects and minimal floor effects were observed.

Conclusion: Within the limitations of the study, the instrument demonstrated strong validity and reliability, offering a comprehensive tool to assess caregiver-reported OHRQoL in children with intellectual disabilities. Further validation across diverse settings and longitudinal evaluation are recommended.