Development of two community-based interventions targeting inappropriate antibiotic dispensing and use behaviours in rural Vietnam Between 2000 and 2010, worldwide antibiotic consumption increased by 35%, including large rises in the use of antibiotic drugs used as a last-resort, when other treatments fail. This rise was particularly apparent in middle income countries, with growing populations and increasing access to antibiotics. Rising levels of antibiotic consumption are associated high levels of antibiotic resistance, and increasing numbers of bacterial infections that are difficult or impossible to treat with antibiotics. Reducing inappropriate antibiotic use has been shown to reduce the level of antibiotic resistance at population-level in high income countries, but few population-level interventions aiming to reduce antibiotic use have been evaluated in low and middle income countries with higher burdens of infectious disease and antibiotic resistance.  This development grant will inform the design of two community-based interventions aiming to reduce inappropriate antibiotic use and related antibiotic resistance. One intervention will target the supply of antibiotics through private pharmacies, the major source of treatment for minor illness, and where antibiotics can easily be obtained without a prescription. Introducing a rapid diagnostic test in this setting would help pharmacists to differentiate between people with non-bacterial infections that do not require antibiotics, and those with likely bacterial infections that should be referred to a health professional. The other intervention will tackle the demand for antibiotics in communities by using participatory discussion in groups to improve understanding of the problem of antibiotic resistance, and develop appropriate strategies to address it in their community.   To assist intervention development, we will conduct a review of the literature to learn from other successful approaches using rapid diagnostic tests outside the formal healthcare system, and health behaviour change interventions in communities. We will collect information from providers and consumers of antibiotics in communities, to understand what drives inappropriate use, and we will also explore their views about the introduction of rapid diagnostic tests in pharmacies, and what price would be attractive for both. We will work with community members, using visual media to develop materials and messages that can be used to talk about antibiotic resistance with other communities.  On finalising the design of the interventions, a methodology will be developed to evaluate and understand the effect of these interventions, with input from experts and local partners. Funding sources will be identified to implement the interventions and research the effect of community-based interventions on antibiotic use and resistance in rural Vietnam. We will disseminate our learning from this process through international peer reviewed publications, briefing papers, and discussions with local partners and community participants. 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.