Validation of the language development survey (LDS): A parent report tool for identifying language delay in toddlers

Two studies are reported demonstrating the reliability validity, and clinic al utility of the Language Development Survey (LDS; L. Rescorla, 1989) as a screening tool for the identification of expressive language delay in todd lers. In Study 1,422 children (ages 24-26 months) were screened with the LD S in an epidemiological survey. The LDS manifested excellent concurrent val idity with a brief direct screening measure of expressive vocabulary. Using the Rescorla (1989) Delay 3 cutoff of fewer than 50 words or no word combi nations, 9.7% of the sample were language delayed (32 boys, 9 girls). In St udy 2, 33 children identified as "at-risk" by the LDS Delay 3 cutoff and 33 typically developing children, matched on age, socioeconomic status, and g ender, were seen for in-depth follow-up assessment approximately 3 weeks la ter. The LDS test-retest reliability was .97. The LDS correlated highly wit h Reynell Receptive and Expressive language Scale scores, Bayley Mental Dev elopment Index, and Vineland Adaptive Behavior Composite. Sensitivity, spec ificity, positive predictive value, and negative predictive value between t he screening LDS and the follow-up Reynell Expressive language Scale were g enerally impressive. Finally, the at-risk group scored significantly lower than the LDS-identified typically developing group on all follow-up measure s except the Child Behavior Checklist/2-3.