The efficacy of treatment for children with developmental speech and language delay/disorder: a meta-analysis

Why the study was done

Many young children have speech or language delays that are not caused by another condition. Families and clinicians need to know which kinds of therapy help, and for which skills. This review brought together the controlled trials available at the time to answer that question.

What the researchers did

The authors found 36 articles describing 33 trials of therapy for children with primary speech and language delay or disorder. Twenty-five had enough information to analyze, and 13 were similar enough to combine statistically. The trials compared therapy with no treatment, with general language stimulation, or with routine therapy.

They looked at results for speech sounds (phonology), vocabulary and grammar (syntax), both for what children could say (expressive) and what they could understand (receptive).

What they found

• Therapy looked effective for children with speech-sound difficulties and for children with expressive vocabulary difficulties.
• Results for expressive grammar were mixed.
• There was very little evidence about therapy for understanding language (receptive skills).
• Interventions delivered by trained parents and by clinicians did not differ significantly.
• Therapy lasting longer than 8 weeks appeared more likely to lead to good outcomes.

What this means for families

Speech and language therapy has research support, especially for speech-sound and vocabulary goals. Two findings shape how we work: parents who are trained in the strategies can make a real difference, and progress takes consistent practice over weeks, not a single visit. That is why our sessions include parent coaching and a plan that runs long enough to see change.

Limits of the study

Only 13 of the eligible trials could be combined, and they were spread over 25 years, so the authors described their conclusions as tentative. They also pointed to gaps in the research, especially for receptive language.