Project Summary/Abstract This proposal seeks continued support to expand a powerful new resource for cross-national health research. IPUMS-DHS (http://www.idhsdata.org) unlocks access to the Demographic and Health Surveys (DHS), the world's primary source of information on fertility, contraceptive use, infant and maternal health, acute illness and nutrition in young children, infant and maternal mortality, domestic violence, marriage and sexuality, HIV/AIDS knowledge and prevalence, and gender attitudes in low- and middle-income countries from the 1980s forward. As of our May 2016 data release, IPUM-DHS incorporates 90 DHS surveys and over 2000 integrated variables for 19 sub-Saharan African countries plus Egypt and India—13 more surveys than promised in the original application. Although the integrated data have only been online for two years, the project has already attracted over 400 users from 61 countries and 253 institutions. IPUMS-DHS eliminates multiple barriers to efficient and accurate use of the DHS, but additional work is required to fully realize the comparative potential of these valuable surveys, which have been fielded in over 90 countries. The next phase of IPUMS-DHS will address four specific tasks: (1) Expand IPUMS-DHS coverage geographically, by including remaining sub-Saharan African countries and adding North Africa, the Middle East, and South Asia, and topically, by harmonizing the challenging anthropometric and calendar variables for adults and incorporating more country-specific variables; (2) Double the number of units of analysis, facilitating research on men, couples, and households in addition to currently available data on women, children, and births; (3) Create contextual variables by linking small DHS geographic units (GPS points) to IPUMS- International census microdata and other sources of land-use and environmental data; and (4) Provide additional online tools, such as improved search capacity, a flexible online tabulator, and multi-language videos and exercises. The proposed work will be carried out by a team of highly-skilled researchers with extensive experience in data integration and in substantive research based on the DHS. ICF International (the organization that collects the original data) will provide expert advice and feedback. The project will employ cutting-edge software innovations, established metadata standards, and vigorous outreach to the global research community.