Psychometric validation and reliability of the Turkish version of the caries impacts and experiences questionnaire for children (CARIES-QC).

Abstract

Objectives: The Caries Impacts and Experiences Questionnaire for Children (CARIES-QC) is a disease-specific patient-reported outcome measure (dPROM) developed to capture, from a first-person perspective, the impact of dental caries on the quality of life of children. The present study aimed to translate and culturally adapt the CARIES-QC into Turkish (CARIES-QC/T) and to assess its reliability and validity in a sample of Turkish-speaking children with active dental caries.

Materials and methods: Translation and cultural adaptation of the CARIES-QC into Turkish were carried out following internationally recognised guidelines for the cross-cultural adaptation of health-related quality-of-life instruments. The adapted questionnaire (CARIES-QC/T) was administered to 307 children aged 5-15 years with active dental caries. Internal consistency was evaluated using Cronbach's α and the inter-item correlation matrix. Test-retest reliability was assessed in a subgroup of 60 participants who completed the questionnaire again after a four-week interval, using intraclass correlation coefficients (ICC). Construct validity was examined through confirmatory factor analysis (CFA) of the hypothesised single-factor structure, and convergent validity through the Spearman correlation between the total CARIES-QC/T score and the single global item.

Results: The sample comprised 307 children (152 girls, 49.5%; 155 boys, 50.5%) aged 5-15 years. The CARIES-QC/T showed high internal consistency (Cronbach's α = 0.919), with inter-item correlations ranging from 0.251 to 0.677. Test-retest reliability was high, with a total-score ICC of 0.918 and item-level ICCs ranging from 0.724 to 0.912. Confirmatory factor analysis supported the hypothesised single-factor structure; model fit indices were at the borderline of conventional thresholds (χ²/df = 4.50, RMSEA = 0.10, GFI = 0.870, CFI = 0.896, TLI = 0.873), with standardised factor loadings of 0.46-0.82. Convergent validity, assessed against the global item, was strong (Spearman's ρ = 0.937, p < 0.001).

Conclusions: Taken together, these findings indicate that the CARIES-QC/T demonstrates adequate psychometric properties for assessing caries-specific oral health-related quality of life in Turkish-speaking children. However, the borderline confirmatory factor model fit and the absence of longitudinal evidence indicate that further evaluation is required before the instrument can be recommended as a fully established outcome measure.

Clinical relevance: A Turkish version of the CARIES-QC with documented internal consistency and test-retest reliability provides clinicians and researchers with a feasible, child-reported instrument for assessing caries-specific impacts on quality of life in Turkish-speaking children, pending further evidence on responsiveness and measurement invariance across age groups.