Verbal Autopsy with Participatory Action Research (VA-PAR): Developing a people-centred health systems research methodology Recent estimates suggest that two-thirds of the world's deaths pass unrecorded. This situation seriously limits the ability of health systems to respond to the needs of vulnerable and excluded populations. Developing methods to reliably understand why people die in populations with weak health systems is therefore an important strategy for saving lives.   Registering medical cause of death has long been considered essential for public health. Despite increasing globalisation, in many resource-poor countries, universal registration of vital events remains lacking and uncertain estimates provide an inadequate basis for policy and planning. In addition, the social inequalities and social contexts play an important role in shaping health for disadvantaged groups. Even with the data available, insufficient attention is paid to the root causes of mortality in resource poor settings.  Considering these factors, there is an urgent need to improve health information about and for marginalised populations to inform public health responses. The proposed research will develop an extension to an established method called Verbal Autopsy (VA). VA is used to measure the levels and causes of death in populations where large numbers die outside health facilities or without registration. The development will help local health systems to assess their own health situations, identify priorities and develop action plans for positive health change.   We will do this through three phases of work.  - Firstly, we will develop improved ways to classify causes of death by combing information on medical causes with data on the circumstances of deaths (seeking and using care at the time of death). In settings where health services are under-funded, weak and fragmented, these can often play a crucial role. The classifications will also be developed in consultation with local health planners to be of practical use. - Secondly, we will develop an additional method to gain the views of local communities on long-standing health challenges. This will allow us to further understand how social, economic and health systems issues influence availability, accessibility, acceptability, and quality of care. The method may also help foster social inclusion in health.  - In the final phase, we will consult with higher levels of the health system about the method. This will help develop how we use the extended cause of death classifications combined with community knowledge. The aim here is to explore how the method could be used in an ongoing fashion to connect health surveillance to service organisation in an inclusive process. This approach encourages sustainable health gains.  Data, poverty and inequality exist in complex co-dependency: less data exist on the health of the poor than the rich, raising important questions about the relationship between material and data poverty. In settings where health systems are fragile and under-resourced, where new burdens of disease are rapidly emerging, and where large and diverse populations are excluded from access to health care, innovative approaches that connect the registration of vital events to health care systems in a people-centred approach are needed.    The approach employs a bottom up philosophy connecting with population data at source. In the longer term, it is envisaged that the method will contribute to more rigorous health data at population level in an inclusive process that can affect sustainable health gains through better data and improved capacity for evaluation.   The work will be conducted in an research centre in rural South Africa established for over 20 years. The extent of data available and the richness of experience in health research allows us to develop a method with partners who enact a broader commitment to registration of all individuals within a population. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.