Systematic review of the literature on the treatment of children with late language emergence.

BACKGROUND Research has indicated that 24-36-month-olds with late language emergence ('late talkers') are at risk for later language-learning difficulties. Previous reviews have examined the efficacy of treatment for children with language delay/disorders; however, no systematic review has examined the effects of language treatment specifically for children with late language emergence. AIMS This systematic review reports the effects of intervention studies conducted between 1985 and 2008 of 24-36-month-olds with late language emergence. MAIN CONTRIBUTION Eleven studies that included a total of 275 participants were located, synthesized, and appraised for quality. Studies varied significantly with respect to methodological quality, with seven of the eleven receiving moderately strong quality scores. OUTCOMES & RESULTS Treatment for children with late language emergence improved performance on formal measures of language, mean length of utterance, and target word use as indicated by medium to large effect sizes in these good-quality studies. Treatment descriptions and clinical implications are provided. CONCLUSIONS & IMPLICATIONS There is evidence to suggest that focused stimulation and modelling of single words can lead to improvements in the language of children with late language emergence. Subsequent treatment studies should examine the application of these effective treatments to larger, population-based samples. Future treatment studies would also benefit from specific examination of children's receptive language level and inclusion of children with late language emergence who vary in socio-economic status and/or ethnicity.