Antibiotics and Activity Spaces: An Exploratory Study of Behaviour, Marginalisation, and Knowledge Diffusion Antimicrobial resistance (AMR) is a global health threat that endangers the achievement of the Sustainable Development Goals, especially Goal 3 on "Good Health and Well-Being." Leading UK and global strategy papers aiming at improving people's antibiotic usage to fight and prevent AMR thereby focus exclusively on awareness-raising campaigns, but this narrow approach suffers from conceptual, methodological, and empirical weaknesses. In response, our study intends to improve the understanding of patients' antibiotic-related health behaviour to inspire more targeted and unconventional interventions in low- and middle-income countries (LMICs). Speaking to the themes of "awareness and engagement" and "informal markets and access to antibiotics," we will investigate three research questions: RQ1. What are the manifestations and determinants of problematic antibiotic use in patients' healthcare-seeking pathways? RQ2. Will people's exposure to a behavioural health systems intervention diffuse or dissipate within a network of competing healthcare practices? RQ3. Which proxy indicators facilitate the detection of problematic antibiotic behaviours across and within communities? Our interdisciplinary approach frames behaviour within a shared activity space. By drawing on theories and tools from public health, medical anthropology, sociology, and development economics, and by focusing on vulnerable rural dwellers in the DAC countries Thailand and Laos, we will be able to generate innovative and unprecedentedly detailed open-access survey data on antibiotic-related behaviour and its social, economic, and spatial determinants. We aim to maximise complementarities with other ongoing projects in the region that (1) implement biomarker testing and education campaigns in clinical settings, (2) generate mixed-method evidence on cross-cultural patterns of antibiotic use, and (3) engage with the general public to improve global health awareness. We will apply a rigorous three-stage stratified cluster random sampling design to produce district-level representative survey data of the antibiotic use of 2,400 villagers; and we will carry out social network censuses in four communities with a total of 2,400 villagers. Using satellite imagery and digital data collection tools, we can realise these sample sizes at 75% of the cost of conventional survey approaches. Pursuant to our research questions, we will generate novel insights into the nature and variability of Thai and Lao antibiotic usage and health behaviours using the following methods: We will (1) use event sequence analysis and multilevel regression to investigate the impact of technology and digital media as well as economic, social, and spatial characteristics of patients on adverse antibiotic usage, (2) apply social network analysis to understand how knowledge and practice diffuse from clinical interventions into village communities, and (3) use latent class analysis to detect problematic conditions for antibiotic use through easy-to-collect proxy indicators. Under the umbrella of the Oxford Tropical Network-an inspiring and enabling research environment-this project will be made possible through collaboration across world-leading researchers and groups in health behaviour research (KEMRI Wellcome Trust Research Programme; Kenya), health economics and public engagement (Mahidol Oxford Tropical Medicine Research Unit in Thailand; LOMWRU in Laos), evidence-based antibiotic policy (Oxford University Clinical Research Unit; Viet Nam), social network analysis (CABDyN Complexity Centre; Oxford), development economics (Technology and Management Centre for Development; Oxford), and global health training (Centre for Tropical Medicine and Global Health; Oxford). ODA relevance follows from our partnerships, capacity building activities, and research interest in vulnerable groups in LMICs. We apply for £249,804 from 1 January 2017 - 31 October 2018 for this pump-priming research. 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.