Development and validation of Language Evaluation Scale Trivandrum for children aged 0-3 years - LEST (0-3)

To develop and validate a simple screening tool which can be used in the Community to identify delay in language development among children of 0-3 years of age. The normal range for the 33-items of "Language Evaluation Scale Trivandrum for 0-3years-LEST(0-3)" were carefully selected from various existing language development charts and scales, by experts keeping in mind the face validity and content validity. The criterion validity was assessed using a community sample of 643 children of 0 to 3 years of age, including 340 (52.9%) boys. LEST (0-3) was validated against Receptive Expressive Energent Language Scale, for screening delay in language development among children of 0-3 years. When one item delay was taken as 'LEST delay' (test positive), the sensitivity and specificity of LEST(0-3), was found to be 95.85% and 77.5%, respectively with a negative predictive value of 99.8% and LR (negative) of 0.05.When two item delay was taken as 'LEST delay' (test positive), the sensitivity and specificity of LEST(0-3), was found to be 66.7% and 94.8% respectively with a negative predictive value of 98.7% and LR (negative) of 0.35. The test-retest and inter-rater reliability were good and acceptable (Interclass correlation of 0.69 for testretest and 0.94 for inter-rater). LEST (0-3) is a simple, reliable and valid screening tool for use in the community to identify children between 0-3 years with delay in language development, enabling early intervention practices.