Over one billion children experience physical, sexual or emotional violence every year and social inequalities in violence are large. The contexts children live, learn and play in can shape their health, employment, and educational outcomes. This project will generate new evidence on how adverse and protective childhood contexts affect children's use, or experiences of, interpersonal violence as they grow up. We propose to draw on high-quality longitudinal data about children's lives, including experiences of violence, in three independent cohort studies in Brazil (birth to late childhood), England (birth to adulthood) and Uganda (late childhood to adulthood). Our multi-country research team consists of social epidemiologists and social scientists with strong links to the settings of each cohort study. To ensure analyses and findings are informed by a wide range of expertise and experiences we will consult local stakeholders (young people, civil society organisations, health workers and local government staff) in each study setting and researchers from different disciplines during research design and dissemination. The World Health Organisation's (WHO) INSPIRE framework recommends changing laws, social norms, social safety nets, neighbourhood environments, households, and schools to prevent interpersonal violence. To advance such prevention efforts, violence researchers and practitioners need to know how childhood contexts shape violence later in life, and how contexts can interrupt or prevent violence later in life. Further, we need to understand if the adverse or protective effects of contexts differ for marginalised young people. The first phase of this project will define and operationalise contextual measures: we theorise that adverse childhood contexts are homes, schools, and neighbourhoods with violence and deprivation, and protective childhood contexts high social connectedness and support. We will use data collected on contexts to operationalise contextual measures specific to each cohort and refine measures based on input from local stakeholders, young people, and researchers in each context. Findings from this phase will highlight new opportunities to apply advanced statistical methods to improve how contexts are measured and defined in violence research. The second phase will test whether adverse childhood contexts increase the risk of violence later in life, and whether protective childhood contexts can mitigate this risk. We aim to conduct causal analyses of longitudinal data to uncover, for example, whether neighbourhood violence and deprivation in childhood could increase interpersonal physical or sexual violence years later - and whether a protective home environment at the same time, or later in life could prevent or interrupt these associations. Findings from this phase provide evidence for developing and situating contextual interventions to prevent violence as children grow up. The third and final phase of the project will explore how the effects of contexts differ for young people from historically marginalised groups. By applying statistical methods to test if the adverse and protective effects of contexts differ by gender, disability, ethnicity, sexuality, and socioeconomic position, findings will highlight which young people are disproportionately impacted by adverse contexts or less likely to benefit from protective contexts. Our approach offers opportunities to improve the use of contextual measures in research on violence and more broadly. Violence prevention efforts at contextual levels shift the loci of intervention away from the individual and are likely to benefit more people than individual-level behaviour change interventions. This research will generate new evidence from multiple countries that researchers and practitioners can use to realise the WHO INSPIRE framework on violence prevention and the Sustainable Development Goals related to violence.

In thirty years' time there will be half a billion adolescents in Africa. Like youth everywhere, they possess huge potential to thrive. But more than half are trapped in cycles of poor nutrition, poverty, low education, violence and unemployment. They also have the world's highest rates of early fertility, with adverse long-term outcomes for adolescent parents and their children. Such inter-generational disadvantage creates risks not only in the region but also to global stability. The SDGs and African Union's Agenda 2063 challenge us to take a radical new approach. The UK's Global Challenges Research Fund provides a unique opportunity to do this. The Accelerating Advantage Hub will find the combinations of services with the greatest positive impacts for Africa's adolescents and their children. We need to move beyond services focused on single outcomes, towards 'super-accelerator' impacts across multiple SDGs of health, education, violence prevention, gender equality and economic stability. With our government partners we will test combination services - for example of cash transfers, malaria prophylaxis, parenting programs, business skills and violence prevention - to identify the leanest and most effective policy packages. The Hub has been planned with African governments and international agencies including the UN Development Program, African Union, UNICEF and the World Health Organisation. They have told us that 'evidence as usual' is not enough. When we make a personal investment, like buying a computer, we want to know not only whether it is the most efficient, but also whether it is good value for money and whether we will like to use it. Governments need the same information about services: their effectiveness, their cost-effectiveness, whether they can be delivered through existing health, education and welfare systems, and whether they will be accepted by service providers and by adolescents. The Hub will conduct large-scale studies and use existing data in Angola, Cote D'Ivoire, DRC, Ethiopia, Gambia, Ghana, Guinea, Kenya, Lesotho, Liberia, Malawi, Mali, Mozambique, Nigeria, Senegal, Sierra Leone, South Africa, Somalia, South Sudan, Tanzania, Uganda, Zambia & Zimbabwe. All projects will include cost-effectiveness to assist budget decisions. In short, we will provide African policy-makers with the evidence they need and want to do the best for adolescents. The Hub will also train and support frontline workers to improve services for adolescents across Africa. We will turn evidence into training modules, freely accessible manuals and support materials. We will deliver practitioner training in 34 African countries by working with NGO partners selected for wide regional coverage, for example Paediatric Adolescent Treatment for Africa, the International Rescue Committee, Clowns without Borders and the International AIDS Alliance. Skills-building for young researchers in Africa and the UK is built into the Hub's work. We will support 45 promising young academics and dedicated African policymakers to focus their careers on improving the lives of adolescents and their children. The Hub's work is planned with adolescents themselves. Too many services have failed because they do not appeal to teenagers' aspirations and immediate goals. The Hub will work directly with adolescent advisory groups in Eastern, Western and Southern Africa to co-develop approaches that are not only effective, but also meaningful and fun for those who will use them. We aim to reach 20 million adolescents and their children with effective combinations of services to meet their needs. Between our direct countries of research and our NGO partners, the Hub will actively engage with policymakers, practitioners and adolescents across East, West, Southern and Central Africa and including fragile and war-torn states. We have a common goal: to transform the potential of Africa's adolescents into a thriving future for the continent.