Validation of the English version of the TOY8 developmental screening tool: examining measurement invariance across languages, gender and income groups.

Background: The National Health and Morbidity Survey in Malaysia (2022) revealed a significant increase in developmental delays among young children. Early detection using valid, accessible, and cross-culturally appropriate developmental screening tools is essential. Thus, English-language and Malay versions of the TOY EIGHT developmental screening tool (TOY8) were developed using artificial intelligence and a standardized parent-proxy questionnaire. This study aimed to examine the construct validity and reliability of the English version of TOY8, building on the previously validated Malay TOY8, and to examine measurement invariance across language versions, gender, and income groups.

Methods: TOY8 was designed and developed to screen for developmental problems in children aged 3-5 years in Malay and English by an interdisciplinary research team drawing upon both national and international guidelines, and then reviewed by an expert panel (n = 5). Two samples of parents and their children were recruited: 1767 dyads to complete the English TOY8 and another 1724 dyads to complete the Malay TOY8.

Results: The confirmatory factor analysis results indicated that the model structure of the English TOY8 matched that of the Malay TOY8. The split-half reliability coefficient indicated adequate to high reliability, which is also consistent with the Malay TOY8. Our results showed that all configural and metric invariance models across groups had a good fit to the data, demonstrating that multiple-group confirmatory factor analysis was appropriate. Finally, scalar invariance was only achieved in certain domains across gender and not in language versions or income groups.

Conclusion: The English TOY8 demonstrates construct validity and reliable screening tool for identifying developmental milestones in children aged 3-5 years in Malaysia. In addition, configural and metric invariances across groups in all domains were established, indicating the cross-cultural equivalence of the items, and scalar invariance was established across genders in most 3- to 5-year-old domains. These findings provide preliminary evidence supporting reliability and validity that aligns with previous literature on child development, which indicates a general similarity in the gender and cross-cultural development domains in the first years of life, but not for older children, in terms of language and socioemotional skills.