Peer-reviewed article

Psychometric evaluation of the Korean version of the Child Oral Health Impact Profile administered online among schoolchildren: a cross-sectional study.

Song JS · 9 Jul 2026

Abstract

Background The Child Oral Health Impact Profile (COHIP-34) is a validated instrument used to assess oral health-related quality of life (OHRQoL) in children and adolescents. However, evidence on its reliability and validity is limited when administered online, particularly among school-aged children. This study aimed to assess the reliability and construct validity of the Korean version of the COHIP-34 when administered online to elementary school children participating in a national oral health program. Methods A total of 980 fourth-grade students completed the Korean COHIP-34 using a smartphone-based Google Form. Internal consistency and test-retest reliability were assessed using Cronbach's alpha and the intraclass correlation coefficient, respectively. Convergent and discriminant validity were analysed using self-rated oral health and treatment needs questions, and oral examination results. Exploratory factor analysis (principal component analysis with Promax rotation) and confirmatory factor analyses were conducted, to evaluate the factor structure and overall model fit. Results The COHIP-34 demonstrated good internal consistency (Cronbach's alpha = 0.828) and excellent test-retest reliability (ICC = 0.903). Convergent validity was supported by significant correlations with self-rated oral health (r = 0.399, P < 0.01) and treatment needs (r = -0.263, P < 0.01). Discriminant validity was demonstrated by significantly lower COHIP scores among children with caries experience or malocclusion. Exploratory factor analysis yielded eight factors with eigenvalues ≥ 1.0, explaining 56.1% of the total variance. Examination of the scree plot and parallel analysis indicated that a five-factor solution was more appropriate, which was subsequently confirmed by confirmatory factor analysis showing acceptable fit indices. Conclusion The Korean COHIP-34, administered online, showed acceptable psychometric properties, suggesting that it may be a practical tool for assessing OHRQoL in large-scale epidemiological studies and school-based oral health programs.