Determination of validity and reliability of the Bayley scales in infant and toddler development

Abstract

Introduction: For diagnosing children who are suspected to have developmental delay through developmental screening tests, we need a valid and reliable diagnostic tool. The Bayley scales is a well-known diagnostic developmental assessment on cognitive, communication and motor domains. The aim of this study was validity and reliability determination of the Bayley test. Materials and Methods: The method of this study was descriptive-analytic. The test was provided through translation- back translation and cultural adaptation. Content and face validity of tool was determined by experts’ opinions. 260 children aged 1 to 42 months were recruited for developmental assessment by Bayley. Reliability of test was calculated through three methods internal consistency, test-retest and inter-rater. Construct validity was calculated using factor analysis and comparison of the mean scores methods. Results: Participants were 260 children 15 days to 42 months, including 134 boys (51.5%). Cranach’s alpha coefficients were more than 0.76 for all domains. Pearson correlation coefficient in different domains, were at least 0.987 (P< 0.001) in test retest method and 0.991 (P