RESUMO
Introduction: Nonverbal communication (NC) skills develop dramatically during the first year of life. Especially in children with Autism Spectrum Disorder (ASD), inadequacies in these skills in the early period negatively affect language development later. Therefore, early recognition of ASD symptoms is the first step in the diagnosis. The test to screen ASD at the earliest age is the Modified Checklist for Autism in Young Children/M-CHAT in Turkey. However, this test can be used for 18 months or later. In the present study, we aimed to adapt the Childhood Nonverbal Communication Scale (CNCS) to Turkish, which was developed in Iran to evaluate NC skills in children from birth to 18 months and determine psychometric properties. Methods: This cross-sectional and methodological study was conducted in 3 provinces and included 323 parents of children who are normally hearing and 3-18 months old. Sociodemographic form, Ankara Development Screening Inventory, CNCS-Turkish form, and LittleEARS Auditory Questionnaire were applied. Results: CNCS Turkish form consisting of 37 questions shows a two-factor structure. The reliability coefficient of the 37-item scale is highly reliable (KR-20=0.937). It also had good convergent validity based on a significant correlation between total scores and LittleEARS results (r=0.804, P<0.001). According to the normative curve plotted by the CNCS total score for age, NC skills progressed with a steep slope from 3 to 12 months and then progressed gradually until 18 months. Conclusions: Childhood Nonverbal Communication Scale (CNCS) is a promising tool showing good validity and reliability in Turkish.