Importance: Training parents to implement strategies to support child language development is crucial to support long-term outcomes, given that as many as 2 of 5 children younger than 5 years have difficulty learning language.
Objective: To examine the association between parent training and language and communication outcomes in young children.
Data sources: Searches of ERIC, Academic Search Complete, PsycINFO, and PsycARTICLES were conducted on August 11, 2014; August 18, 2016; January 23, 2018; and October 30, 2018.
Study selection: Studies included in this review and meta-analysis were randomized or nonrandomized clinical trials that evaluated a language intervention that included parent training with children with a mean age of less than 6 years. Studies were excluded if the parent was not the primary implementer of the intervention, the study included fewer than 10 participants, or the study did not report outcomes related to language or communication.
Data extraction and synthesis: Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were applied to a total of 31 778 articles identified for screening, with the full text of 723 articles reviewed and 76 total studies ultimately included.
Main outcomes and measures: Main outcomes included language and communication skills in children with primary or secondary language impairment and children at risk for language impairment.
Results: This meta-analysis included 59 randomized clinical trials and 17 nonrandomized clinical trials including 5848 total participants (36.4 female [20.8%]; mean [SD] age, 3.5 [3.9] years). The intervention approach in 63 studies was a naturalistic teaching approach, and 16 studies used a primarily dialogic reading approach. There was a significant moderate association between parent training and child communication, engagement, and language outcomes (mean [SE] Hedges g, -0.33 [0.06]; P < .001). The association between parent training and parent use of language support strategies was large (mean [SE] Hedges g, 0.55 [0.11], P < .001). Children with developmental language disorder had the largest social communication outcomes (mean [SE] Hedges g, 0.37 [0.17]); large and significant associations were observed for receptive (mean [SE] Hedges g, 0.92 [0.30]) and expressive language (mean [SE] Hedges g, 0.83 [0.20]). Children at risk for language impairments had moderate effect sizes across receptive language (mean [SE] Hedges g, 0.28 [0.15]) and engagement outcomes (mean [SE] Hedges g, 0.36 [0.17]).
Conclusions and relevance: The findings suggest that training parents to implement language and communication intervention techniques is associated with improved outcomes for children and increased parent use of support strategies. These findings may have direct implications on intervention and prevention.