Predicting Treatment Outcomes in The Helping Children Achieve Randomised Controlled Trial
: Exploring Possible Moderators and Mediators of Treatment Effects on Child Conduct and Literacy.

Student thesis: Doctoral ThesisDoctor of Clinical Psychology


Background and Rationale. Early intervention aims to identify children at risk of later poor outcomes and intervene before they become established. Two malleable risk factors are conduct problems and poor reading, which can both be targeted through parenting programmes. However, trials testing these interventions often find variable effects. Chaos at home, maternal antisocial behaviour, and ADHD symptoms have been found to be identified as possible factors that may moderate the effectiveness of interventions, by making the strategies that the interventions aim to increase less effective. These interventions may also indirectly increase the amount of time parents spend with their child and may therefore be a mediator of treatment effects.

Aims. To test potential moderators and mediators of the Incredible Years Programme and SPOKES programme on child behaviour and reading, for children aged between 5-7 who were identified as at risk of antisocial behaviour problems. Specifically, to test the potentially moderating effects of chaos at home, maternal antisocial behaviour, and child ADHD symptoms on child conduct and reading, and the potential mediating effect of the amount of time parents spend with their child on child conduct and reading.

Method. The Helping Children Achieve Trial was a 3-arm, parallel-group, researcher-blind, multisite randomized clinical trial. 215 children aged between 5-7 wo were identified as at-risk for antisocial behaviour were randomised to receive either the behaviour programme (Incredible Years, IY), reading programme (SPOKES) a combination group or a control group.
Measures of the moderators and mediators were taken at the pre and post-intervention timepoints.

Results. No treatment effects were found for the IY or SPOKES programmes on either child behaviour or reading. A significant moderating effect of chaos at home on reading was found for the SPOKES programme, whereby the intervention was effective but only where levels of chaos were low. A similar pattern of effects was found for the IY programme; however these did not reach significance overall. No moderating effects of chaos at home were found for behaviour outcomes. No moderating effects were found for ADHD or antisocial behaviour, and no mediating effects were found for the amount of time parents spend with their child.

Conclusions. This study suggests that chaos at home may be an important factor to consider when supporting children with learning to read, whereby those children with more chaotic households may not receive the same benefits from programmes as those from low chaos homes. These findings have implications for clinicians but also educators, highlighting the importance of a calm, routine based, predictable home environments. However, this study does have some important limitations, including the timing the moderator was measured and the sample size. Future research should replicate these findings using larger samples and investigate whether these findings would also be applicable in lower-risk samples.
Date of Award1 Feb 2023
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorMatt Woolgar (Supervisor) & Stephen Scott (Supervisor)

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