Psychometric evaluation of the Vietnamese version of the child-OIDP index among adolescents aged 12-15 years.

BACKGROUND: Oral health–related quality of life (OHRQoL) has become an essential dimension for evaluating the functional, psychosocial, and social consequences of oral conditions in children and adolescents. This study aimed to translate, culturally adapt, and psychometrically evaluate the Vietnamese version of the Child-Oral Impacts on Daily Performances (Child-OIDP) index. METHODS: A cross-sectional study was conducted among 505 adolescents aged 12–15 years in Ho Chi Minh City. The translation and cultural adaptation followed international guidelines. Clinical oral examinations were performed using WHO criteria. Psychometric testing included internal consistency, test–retest reliability, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and hypothesis-driven construct validity testing. A subsample of 135 adolescents completed the instrument twice for reliability assessment. RESULTS: Overall, 65.1% of participants reported at least one oral impact. Eating, smiling, and cleaning teeth were the most frequently affected daily performances. The Vietnamese Child-OIDP demonstrated good internal consistency (Cronbach’s alpha = 0.82) and excellent test–retest reliability (ICC = 0.89). EFA supported a three-factor structure representing functional, psychosocial, and social domains, explaining 62.83% of the variance. CFA demonstrated moderate but suboptimal fit (RMSEA = 0.092; CFI = 0.906; TLI = 0.888; GFI = 0.958; SRMR = 0.123). Five of the six predefined hypotheses (83.3%) were confirmed, exceeding the 75% threshold recommended by COSMIN for supporting construct validity. Higher Child-OIDP scores were observed among adolescents with poorer self-rated oral health, perceived treatment need, dental caries, and malocclusion. CONCLUSIONS: The Vietnamese Child-OIDP demonstrates adequate reliability and supported construct validity among adolescents aged 12–15 years. Structural validity should be interpreted cautiously. The instrument provides a culturally appropriate tool for assessing OHRQoL in Vietnamese youth.