Methods: Parents/children dyads (n = 286) recruited as part of a randomised controlled trial on the treatment of early childhood caries completed the ECOHIS at baseline, and 33 parents repeated the questionnaire some 2-3 weeks later. The validity and reliability of ECOHIS was determined using tests for convergent (Spearman’s correlation) and discriminant validity (regression analyses), internal reliability of the instrument (Cronbach’s alpha) and the test–retest reliability (ICC).
Results: ECOHIS scores were strongly correlated with global oral health ratings (Spearman’s correlations; r = 0.53, p < 0.001 total score; r = 0.41, p < 0.001 child impact; and r = 0.54, p < 0.001 family impact). Regression analyses found significant associations with children’s caries experience after controlling for age, p<0.001 for total ECOHIS score, child impact sub-domain and the family impact sub-domain. Cronbach’s alpha values were 0.87 for the entire scale, 0.87 and 0.74 for the child function and the family function domains, respectively. Test-retest reliability ICC was 0.92 for the entire scale and 0.89 and 0.78 for the child function and the family function domains, respectively.
Conclusions: The ECOHIS instrument demonstrated acceptable validity and reliability for assessing the impact of early childhood caries among Australian preschool children.