The validity and reliability of DDST II and Bayley III in children with language development delay

Objective: To analyze and compare the performance of the language sectors in the Denver Developmental Screening Test II (DDST II) and the Bayley Scales of Infant Development III (Bayley III) test with that of the Sequenced Language Scale for Infants (SELSI). Methods: Retrospective medical chart reviews including the Bayley III, DDST II and SELSI were conducted for 35 infants suspected to have delayed language development. More than 1 caution or fail in the DDST II-language sector (DLS) and Bayley III-language sector (BLS) score below 7were regarded as delayed language development. The sensitivity, specificity, positive predictive value, and negative predictive value of the DLS and BLS were analyzed. The degree of agreement between the Bayley III-receptive language sector (BRLS) or Bayley III-expressive language sector (BELS), DLS and SELSI was assessed by Cohen’s kappa. Pearson’s correlation between the Bayley III and SELSI was performed. Results: The DLS and BELS showed high sensitivity, while the BRLS showed low sensitivity. The BRLS showed very high specificity and the BELS showed high specificity; in contrast, the DLS showed low specificity. Cohen’s kappa for the BRLS and DLS with the SELSI indicated moderate, while the value for the BELS indicated good agreement. The equivalent age as assessed by the BRLS or BELS was significantly associated with that assessed by the SELSI. Conclusion: We propose that the DDST II is a useful screening test to identify infants with delayed language development. But the BLS cannot replace the SELSI in the evaluation of language development. Keyword: Language development disorders, developmental disabilities, language development Neurology Asia 2019; 24(4) : 355 – 361 Address correspondence to: Young-Joo Sim, M.D. Ph.D., Department of Physical Medicine and Rehabilitation, Kosin University Gospel Hospital, Kosin University College of medicine, 262 Gamcheon-ro, Seo-gu, Busan, 49267Republic of Korea. Tel: 051-990-6261, E-Mail: oggum@hanmail.net to develop language abilities according to the appropriate developmental timetable. Delayed language development is the most common developmental disorder of children aged between 2 to 4 years with a prevalence of 5 to 10% of all children and a higher incidence in boys than in girls.3,4 Delayed language development may be due to neuropsychiatric or socio-developmental factors as well as physical disabilities such as hearing impairment, structural abnormalities related to pronunciation, and neurological impairment. Problems that manifest at the early stages of development such as gross motor and fine motor impairment are likely to develop into language disorders later on.5-6 For this reason, language development is recognized as a useful developmental indicator reflecting a child’s overall developmental status, including cognitive ability, and also as a reflection of the child’s ability to adapt to school attendance.7-9 Assessing the level of language development is an important factor INTRODUCTION Infants and toddlers experience the greatest developmental changes throughout the human life, including the most significant changes in human behavior and physical, mental, and social development.1 During this period, infants and toddlers begin to show independent behavior, adapt to their environment, and react appropriately. Moreover, they also begin to form relationships with others and their surroundings and experience rapid overall development. Regarding language development, newborns try to communicate through crying and gestures immediately after birth. When infants reach 12 months old, communication develops from primitive sounds to verbal communication, including the generation of meaningful words. By the age of two to three years, children are able to understand and express ideas using the basic grammar of their native language.2 Delayed language development is a failure in children Neurology Asia December 2019 356 in predicting the overall normal development of the child in the future and determining their potential need for treatment. Language skills are one of the most important parts because they are prominent in the infant’s developmental process. Therefore, it is imperative to evaluate and treat infant language disorders at these critical times.10 As a tool for assessing language development in Korea, the Korean version of the sequential language scale for infants (SELSI) has been used in many medical institutions as a standardized test.11 The SELSI requires a relatively long test time of about 30 to 40 minutes and requires a specialized speech therapist to perform the test. Therefore, it is difficult to perform the test if the facility is not appropriately equipped. While it is theoretically important to screen for abnormal language development in infants and toddlers, in clinical practice this decision is often based on the subjective judgment of the clinician. It is very difficult to determine the degree of delayed language development using subjective judgment, especially in younger children whose normal development can vary widely. The purpose of this study was to compare the SELSI with the language development sectors of the Denver Developmental Screening Test II (DDST II) and the Bayley Scales of Infant and Toddler Development 3rd edition (Bayley III) test which are commonly used to screen overall infant development in clinical practice. The validity of each test was calculated. The degree of agreement with the SELSI was analyzed to evaluate the reliability of the two tests and to test the accuracy of the test as a diagnostic test. In addition, we determined which test was more appropriate as an alternative screening test for the SELSI.