Through our parent-practitioner-community (PPC) partnership, consisting of parents with children involved with social work, infant mental health practitioners, researchers, and community stakeholders, we have coproduced Infant Parent Support teams (IPS), in Glasgow and London. IPS are mental health teams offering high quality therapeutic interventions to struggling families. IPS teams aim to reduce the risk of child maltreatment (CM) and improve parent and child mental health. In this study, we propose to further develop the place-based features of IPS teams and test the clinical and cost-effectiveness of IPS in a definitive randomised controlled trial (RCT). Place-based inequalities in health begin early in childhood: young children experiencing poverty and/or racism are more likely to develop health problems earlier in the lifespan than their peers. Children in the most deprived 10% of small UK neighbourhoods are over 10 times more likely to be in care or on protection plans than children in the least deprived 10%. Social determinants of health and child welfare are "systemic, population-based, cyclical and intergenerational" resulting in certain geographical areas being plagued by overlapping physical and mental health problems and addictions. Infants and preschool children rely on parents and practitioners access services - a process vulnerable to structural inequalities. Our novel aim is to redress this. Our coproduction has led to enhancements of IPS, including neurodevelopmental awareness, poverty awareness, and the employment of parents as practitioners and managers in IPS, and we have mapped the local contexts in which the IPS teams are embedded. We are currently conducting a feasibility randomised controlled trial (f-RCT) investigating how best to involve the families who can benefit most from IPS. In this new study, consisting of four work packages (WPs), we aim to reduce place-based inequalities through: WP1, co-creating a new theory of change for IPS that takes the local context in which IPS teams are embedded into account; WP2, implementing findings from our f-RCT and WP1 to make IPS teams fully place-based, i.e., further embedding IPS teams within their local communities and enhancing each local community's ability to make best use of IPS; WP3 (contiguous with WPs 1, 2 and 4), conducting a definitive RCT to examine the clinical and cost-effectiveness of IPS in reducing the risk of child maltreatment and improving mental health; and WP4, conducting a realist process evaluation examining what works best, for whom and in what context. RCT outcomes will also include measures of community connectedness and IPS costs, consequences and cost-effectiveness. At two adaptation points during the RCT, all four WPs will work with an expert scientific advisory group and the PPC-partnership to examine whether we are reaching our desired target population (including marginalised families) and, if not, to enhance our recruitment strategy to achieve equality of access to the study by employing recruiters who come from or have links with under-served populations, and/or targeting specific geographical areas through our extensive networks across Greater Glasgow and in ten diverse London Boroughs. Our success in reducing place-based inequalities will be measured by whether our RCT has recruited a trial population that demographically mirrors our target population. The techniques most successful in achieving this will inform recommendations for post-trial implementation of IPS to ensure that future IPS teams can reduce place-based inequalities by embedding optimally within their local community/service context, and targeting the families likely to most benefit.

We are a team of people from all walk of life with a shared vision of improving wellbeing for our community on the Fylde coast and for other coastal communities. Coastal communities continue to have more and greater mental and physical health challenges, resulting in lower life expectancy and higher rates of many major diseases compared to their inland neighbours (Chief Medical Officer's Annual Report, 2021). There are a number of well-known factors that contribute to health inequalities in coastal regions, including deprivation, poor housing, and a low-wage economy (Marmot, 2005; Williams & Buck, 2020). All of these place increased demand on overstretched health services. Despite this, large-scale research focusing specifically on coastal communities is scarce. It is known that community-based support delivered by the VCFSE sector has the potential to reduce the burden on public health services, which has been especially important during the Covid-19 pandemic (Stansfield et al., 2020). VCFSE organisations are close to communities, they have skills in and experience of working with the most disadvantaged members of the community often considered 'hard to reach', they have the flexibility to respond to community needs and deliver effective interventions (Department of Health, 2008; Local Government Association, 2017; Allison, 2010). However, there are barriers in the commissioning process, e.g. lack of financial resources, and challenges in the evaluation strategies, e.g. limited evaluation literacy, technical capability, and knowledge of relevant outcome indicators, which makes it difficult for these organisations to be recognised and for their important work to become sustainable (Bach-Mortensen & Montgomery, 2018). We will mobilise our community's assets by uniting members of the public, community-based practitioners, and commissioners on the Fylde Coast to work together and improve partnership, service provision, and research. To do this, we first need to understand what is currently being delivered in the area; and so we will map out and engage the fullest possible range of community-based support providers. We will establish and test a model of working together. This model will include three co-production groups; each will focus on a specific task and work towards equally important aims. These groups will be led by co-researchers with relevant expertise by discipline or experience. Group 1 will unite lived-experience experts and practitioners, will use creative methods (e.g., PhotoVoice) to imagine the future of a community-hub that can integrate a broader range of available community-based support in response to the needs of the community. The aim is to enable lived-experience experts to become 'shapers and makers' of their own care provision rather than 'users and choosers' of it (Cornwall & Gaventa, 2000). Group 2 will provide a dedicated space for the public and VCFSE sector support providers to discuss the key barriers to cross-sector partnership working, co-produce an action plan to overcome these barriers, and establish shared goals, vision, and language. Group 3 will be called the Research Consortium, and will unite key stakeholders, including lived-experience experts. They will conduct a consultative rapid review on main drivers of ill-health in coastal communities, learn from Group 1 and 2, co-produce a five-year research plan, and establish an integrated research infrastructure (i.e. data sharing agreements, data warehouse, core outcome measures) enabling them to conduct research that will benefit people on the Fylde Coast and beyond. In parallel, regular open research workshops will be held to build research capacity in the community. We will test the impact of our activities on network patterns using social network analysis. We will connect with other coastal communities, including Hastings, with similar characteristics and health outcomes to share learning and lay the foundations of future collaborations.