Two-Year Outcomes of a Population-Based Intervention for Preschool Language Delay: An RCT.

OBJECTIVE: We have previously shown short-term benefits to phonology, letter knowledge, and possibly expressive language from systematically ascertaining language delay at age 4 years followed by the Language for Learning intervention. Here, we report the trial's definitive 6-year outcomes. METHODS: Randomized trial nested in a population-based ascertainment. Children with language scores >1.25 SD below the mean at age 4 were randomized, with intervention children receiving 18 1-hour home-based therapy sessions. Primary outcome was receptive/expressive language. Secondary outcomes were phonological, receptive vocabulary, literacy, and narrative skills; parent-reported pragmatic language, behavior, and health-related quality of life; costs of intervention; and health service use. For intention-to-treat analyses, trial arms were compared using linear regression models. RESULTS: Of 1464 children assessed at age 4, 266 were eligible and 200 randomized; 90% and 82% of intervention and control children were retained respectively. By age 6, mean language scores had normalized, but there was little evidence of a treatment effect for receptive (adjusted mean difference 2.3; 95% confidence interval [CI] -1.2 to 5.7; P = .20) or expressive (0.8; 95% CI -1.6 to 3.2; P = .49) language. Of the secondary outcomes, only phonological awareness skills (effect size 0.36; 95% CI 0.08-0.65; P = .01) showed benefit. Costs were higher for intervention families (mean difference AU$4276; 95% CI: $3424 to $5128). CONCLUSIONS: Population-based intervention targeting 4-year-old language delay was feasible but did not have lasting impacts on language, possibly reflecting resolution in both groups. Long-term literacy benefits remain possible but must be weighed against its cost.

Improving outcomes of preschool language delay in the community: protocol for the Language for Learning randomised controlled trial.

BACKGROUND: Early language delay is a high-prevalence condition of concern to parents and professionals. It may result in lifelong deficits not only in language function, but also in social, emotional/behavioural, academic and economic well-being. Such delays can lead to considerable costs to the individual, the family and to society more widely. The Language for Learning trial tests a population-based intervention in 4 year olds with measured language delay, to determine (1) if it improves language and associated outcomes at ages 5 and 6 years and (2) its cost-effectiveness for families and the health care system. METHODS/DESIGN: A large-scale randomised trial of a year-long intervention targeting preschoolers with language delay, nested within a well-documented, prospective, population-based cohort of 1464 children in Melbourne, Australia. All children received a 1.25-1.5 hour formal language assessment at their 4th birthday. The 200 children with expressive and/or receptive language scores more than 1.25 standard deviations below the mean were randomised into intervention or 'usual care' control arms. The 20-session intervention program comprises 18 one-hour home-based therapeutic sessions in three 6-week blocks, an outcome assessment, and a final feed-back/forward planning session. The therapy utilises a 'step up-step down' therapeutic approach depending on the child's language profile, severity and progress, with standardised, manualised activities covering the four language development domains of: vocabulary and grammar; narrative skills; comprehension monitoring; and phonological awareness/pre-literacy skills. Blinded follow-up assessments at ages 5 and 6 years measure the primary outcome of receptive and expressive language, and secondary outcomes of vocabulary, narrative, and phonological skills. DISCUSSION: A key strength of this robust study is the implementation of a therapeutic framework that provides a standardised yet tailored approach for each child, with a focus on specific language domains known to be associated with later language and literacy. The trial responds to identified evidence gaps, has outcomes of direct relevance to families and the community, includes a well-developed economic analysis, and has the potential to improve long-term consequences of early language delay within a public health framework. TRIAL REGISTRATION: Current Controlled Trials ISRCTN03981121.