Purpose: To evaluate the efficacy of a 6-month course of responsivity education/prelinguistic milieu teaching (RE/PMT) for children with developmental delay and RE/PMT's effects on parenting stress in a randomized clinical trial.
Method: Fifty-one children, age 24-33 months, with no more than 10 expressive words or signs, were randomly assigned to treatment/no-treatment groups. Thirteen children in each group had a diagnosis of Down syndrome.
Results: In 1 of 2 multivariate comparisons, the RE/PMT group exhibited superior gains in communication compared with the no-treatment group. The treatment effect for overall use of intentional communication acts in the child-examiner context was significant (d = .68, 95% confidence interval = 0.12-1.24). There were no effects on child outcomes due to presence or absence of Down syndrome. RE/PMT led to modest increases in recoding of child acts by parents of children who did not have Down syndrome. There were no effects on parenting stress associated with the intervention or the presence or absence of Down syndrome.
Conclusions: RE/PMT may be applied clinically with the expectation of medium-size effects on the child's rate of intentional communication acts after 6 months of intervention. The approach warrants further investigation with modifications, such as delivery at higher intensity levels.