Parent-mediated early intervention for young children with autism spectrum disorders (ASD)

Background

Young children with autism spectrum disorders (ASD) have impairments in the areas of communication and social interaction and often display repetitive or non-compliant behaviour. This early pattern of difficulties is a challenge for parents. Therefore, approaches that help parents develop strategies for interaction and management of behaviour are an obvious route for early intervention in ASD. This review updates a Cochrane review first published in 2002 but is based on a new protocol.

Objectives

To assess the effectiveness of parent-mediated early interventions in terms of the benefits for both children with ASD and their parents and to explore some potential moderators of treatment effect.

Search methods

We searched a range of psychological, educational and biomedical databases including CENTRAL, MEDLINE, Embase, PsycINFO and ERIC in August 2012. As this is an update of a previous review, we limited the search to the period following the original searches in 2002. Bibliographies and reference lists of key articles were searched, field experts were contacted and key journals were handsearched.

Selection criteria

We included only randomised controlled trials of early intervention for children with ASD. The interventions in the experimental condition were mediated by parents; the control conditions included no treatment, treatment as usual, waiting list, alternative child-centred intervention not mediated by parents, or alternative parent-mediated intervention of hypothesised lesser effect than the experimental condition.

Data collection and analysis

Two review authors (HM and IPO) independently screened articles identified in the search and decided which articles should be retrieved in full. For each included study, two review authors (IPO and EH) extracted and recorded data, using a piloted data collection form. Two review authors (IPO and HM) assessed the risk of bias in each study. We performed data synthesis and analysis using The Cochrane Collaboration's Review Manager 5.1 software.

Main results

The review includes 17 studies from six countries (USA, UK, Australia, Canada, Thailand and China), which recruited 919 children with ASD. Not all 17 studies could be compared directly or combined in meta-analyses due to differences in the theoretical basis underpinning interventions, the duration and intensity of interventions, and the outcome measurement tools used. Data from subsets of 10 studies that evaluated interventions to enhance parent interaction style and thereby facilitate children's communication were included in meta-analyses. The largest meta-analysis combined data from 316 participants in six studies and the smallest combined data from 55 participants in two studies. Findings from the remaining seven studies were reported narratively.

High risk of bias was evident in the studies in relation to allocation concealment and incomplete outcome data; blinding of participants was not possible.

Overall, we did not find statistical evidence of gains from parent-mediated approaches in most of the primary outcomes assessed (most aspects of language and communication - whether directly assessed or reported; frequency of child initiations in observed parent-child interaction; child adaptive behaviour; parents' stress), with findings largely inconclusive and inconsistent across studies. However, the evidence for positive change in patterns of parent-child interaction was strong and statistically significant (shared attention: standardised mean difference (SMD) 0.41; 95% confidence interval (CI) 0.14 to 0.68, P value < 0.05; parent synchrony: SMD 0.90; 95% CI 0.56 to 1.23, P value < 0.05). Furthermore, there is some evidence suggestive of improvement in child language comprehension, reported by parents (vocabulary comprehension: mean difference (MD 36.26; 95% CI 1.31 to 71.20, P value < 0.05). In addition, there was evidence suggesting a reduction in the severity of children's autism characteristics (SMD -0.30, 95% CI -0.52 to -0.08, P value < 0.05). However, this evidence of change in children's skills and difficulties as a consequence of parent-mediated intervention is uncertain, with small effect sizes and wide CIs, and the conclusions are likely to change with future publication of high-quality RCTs.

Authors' conclusions

The review finds some evidence for the effectiveness of parent-mediated interventions, most particularly in proximal indicators within parent-child interaction, but also in more distal indicators of child language comprehension and reduction in autism severity. Evidence of whether such interventions may reduce parent stress is inconclusive. The review reinforces the need for attention to be given to early intervention service models that enable parents to contribute skilfully to the treatment of their child with autism. However, practitioners supporting parent-mediated intervention require to monitor levels of parent stress. The ability to draw conclusions from studies would be improved by researchers adopting a common set of outcome measures as the quality of the current evidence is low.

Plain Language Summary

Early intervention delivered by parents for young children with autism spectrum disorders

Autism spectrum disorders (ASD) affect more than 1% of children and is usually evident in behaviour before the age of three years. A child with ASD lacks understanding of how to interact with another person, may not have developed language or understand other people's communication, and may insist on routines and repetitive behaviours. This early pattern of difficulties is a challenge for parents. Therefore, helping parents to develop strategies for interaction and management of behaviour is an obvious route for early intervention. The present review brings up to date one published in 2003, which found only two well-designed studies. This review, based on a new protocol, includes 17 randomised controlled trials, most published since 2010, in which interventions delivered by parents were compared with no treatment or local services, or alternative child-centred intervention such as nursery attendance, or another parent-delivered intervention that differed in some way from the main condition. We were able to combine outcome information and so increase confidence in the results. All the studies were rated on the quality of their evidence, which was then taken into account in judging how firmly conclusions could be drawn.

The studies varied in the content of what parents were trained to do, and over what length of time parents had contact with professionals. Parents received training either individually with their child or in groups with other parents. In the majority of the studies, the interventions aimed to help parents be more observant and responsive during interactions with their child in order to help their child develop communication skills. 

In summary, the review finds sufficient evidence that the ways in which parents interacted with their children did change as intended. The review also suggests improvement in child outcomes such as understanding of language and severity of autism characteristics as a result of interventions delivered by parents. However, important outcomes such as other aspects of children's language, children's adaptive skills and parent stress did not show change. The evidence is not yet strong for any outcome and would benefit from researchers measuring effects in the same ways.