Effectiveness of an Implementation Optimisation Intervention Aimed at Increasing Parent Engagement in HENRY, a Childhood Obesity Prevention Programme: a Cluster Randomised Controlled Trial

BACKGROUND: Rising rates of obesity in preschool children are alarming and emphasise the need for evidence-based approaches to prevent obesity, which can be successfully implemented in communities. Although robust, theory-based prevention programmes exist, it is often a challenge to get parents to attend them and adopt positive behaviour changes in their families.

AIM: To evaluate the effectiveness of a recently developed 'Optimisation intervention' to optimise parent engagement in a community based obesity prevention programme 'HENRY', using routinely collected process data from existing sites commissioned to deliver HENRY in the UK

DESIGN: Multi-centre, cluster randomised controlled trial. As research will judge the ability of local authorities and their Centres to optimise implementation of HENRY, a cluster randomised design, has been chosen with local authority as the unit of randomisation. Local authorities will be randomised in a 1:1 allocation ratio (HENRY+ Optimisation Intervention; HENRY alone control) by a statistician at Leeds CTRU, using minimisation algorithm with random element, stratifying on baseline level of implementation (proportion of Centres meeting none of the 2 primary outcome implementation criteria/ meeting 1 or 2 of the criteria)) size of local authorities (number of Children's Centres (< 10/ ≥10)) and area deprivation (≤10% />10% ranking within Index of Multiple Deprivation at the Lower Layer Super Output Area).

Consent to participate will be sought at the cluster level (local authorities) and from the Centres within each local authority using an opt-out approach.

CONTROL ARM: HENRY delivered as standard. HENRY (Health, Exercise, Nutrition for the Really Young) is an 8-week programme delivered in Children's Centres (CCs), aiming to provide parents with skills and knowledge to support healthy lifestyles in preschool children and their families. It was set up in 2006 with Department of Health support aimed at reversing rising trends in school entry age obesity. HENRY is currently delivered in 32 local areas across England and Wales by trained health and community practitioners.