Psychometric evaluation of the Thai version of Early Childhood Oral Health Impact Scale (Th-ECOHIS): a cross sectional validation study

Abstract

Background: Early childhood caries (ECC) is prevalent in Thailand. There has never been an appropriate tool to measure its impact on children. This study translated Early childhood oral health impact scale (ECOHIS), a widely used proxy-reported questionnaire developed in the United States for measuring the oral health related quality of life of preschool children and their families and adopted into many countries, into Thai (Th-ECOHIS). Its psychometric properties were investigated in Thai caregivers and their children. Methods: Cultural adaptation for the scale development within Thai context was processed using forward–backward translation by experts. A face and content validation test were conducted among a group of 20 caregivers to attain the final Th-ECOHIS. Psychometric testing was done on 3-year-old-child-caregiver pairs in Bangkok with the interviewer-administered mode. Children’s oral health was indicated by caries experience (decayed, missing and filled primary teeth, dmft) and treatment need. The caregivers answered the Th-ECOHIS and global questions regarding perception of their children’s oral health. Reliability was assessed by measuring internal consistency and reproducibility using Cronbach’s alpha coefficient. Test-retest reliability was managed at 2-week interval in 10% of samples using the intraclass correlation coefficient calculated by two-way analysis of variance. The discriminant validity was tested by the relationship between the severity of dental caries, treatment need and Th-ECOHIS scores using Kruskal-Wallis test.Results: A total of 214 child-parent pairs participated. Twenty-two percent had ECC (dmft 1-3) and 17.3% had severe ECC (dmft 4 or higher) with mean (SD) dmft 1.63 (2.92). All items in the original ECOHIS were retained in the Thai version. The test-retest reliability of Th-ECOHIS was 0.87; internal consistency was 0.85; the total of Th-ECOHIS scores were significantly correlated with the global rating of oral health question (r = 0.604). Th-ECOHIS scores in both child and family impact sections and total were significantly associated with the severity of caries (p < 0.001) and treatment need (p < 0.001).Conclusions: Th-ECOHIS demonstrated good reliability and validity. It could be used to assess the impacts of ECC on quality of life of Thai pre-school children through caregiver and compare to other countries.