24 Feb 2021

Spatial Anonymization in Household Surveys

Location is an important factor in population and health outcomes. Knowing the geospatial location of household survey clusters allows researchers to analyze the impact of location on peoples’ health, nutrition, and access to health care services. Geospatial data provide a clearer picture of where progress towards the Sustainable Development Goals is and is not being made at subnational levels.

The United Nations’ Inter-Secretariat Working Group on Household Surveys (ISWGHS) was convened to identify priority areas for household surveys to meet new data demands and increase their impact on policy and research over the next decade of the 2030 Agenda for Sustainable Development. Under the ISWGHS, The DHS Program and the World Bank co-led a task force on Spatial Anonymization of Public-Use Household Survey Datasets.

The DHS Program has collected GPS coordinates for household survey clusters since 1996. To ensure respondent confidentiality and prevent positive identification (disclosure) of respondent locations, the GPS position of each urban cluster is displaced by up to two kilometers and up to 5-10 kilometers for rural clusters. This method of geomasking coordinates developed by The DHS Program is straightforward and has been widely accepted by analysts using DHS geospatial data. Nonetheless, there are legitimate concerns that urban points may be overly displaced, reducing the analytical usefulness of the geospatial data, and that some rural points may not be adequately displaced to ensure respondent confidentiality. In response, the spatial anonymization task force convened to explore more sophisticated methods of anonymizing geospatial data.

The task force developed and tested new population-based displacement tools on multiple DHS survey datasets. These tools use an area’s population to determine the minimum distance a cluster’s GPS position must be displaced. These new methods show promise over current spatial anonymization methods to better protect survey respondents while minimizing any adverse impact on analysis and continue to be explored using DHS datasets.

The task force also outlines immediate steps that can be taken to protect respondents. “Even without switching to a new population-based approach [to anonymize geospatial data], we should take steps to verify that we are within an acceptable level of disclosure risk and that our current anonymization objectives are being achieved,” explains Trinadh Dontamsetti, Lead, Geospatial Research. Standards in data protection and security have evolved—the European Union General Data Protection Regulation requires that personal data, including location data, be safeguarded. The task force recommends assessing the risk of disclosure. By quantifying and measuring spatial disclosure risk, the risk can be managed.

Read the “Spatial Anonymization” report for more from the Spatial Anonymization of Public-Use Household Survey Datasets task force. This report was also discussed by stakeholders to prepare a forthcoming paper on “Positioning Household Surveys for the Next Decade.” Both papers will be presented as part of the 52nd Session of the United Nations Statistical Commission: Better Data Better Lives on March 1-3 and 5, 2021.


01 Feb 2021

New Online Course: Health Data Mapping Online Course

The DHS Program is hosting another Health Data Mapping online course on The DHS Program Learning Hub. The 12-week course focuses on the application of geographic information systems (GIS) in public health, specifically using maps for better program and policy decision making. Participants will be introduced to GIS concepts, manage and clean data in Microsoft Excel, and get a hands-on introduction to QGIS, an open-source GIS software package.

This course is for people who:

  • Have little to no GIS experience, but have an interest in learning QGIS and strong data skills.
  • Live and work in a West African country (Benin, Burkina Faso, Cameroon, Cote d’Ivoire, Gambia, Ghana, Guinea, Liberia, Mali, Mauritania, Nigeria, Senegal, Sierra Leone, Togo).
  • Have at least an undergraduate degree in public health, demography, statistics, monitoring & evaluation, or a related subject, and basic training in statistics.
  • Currently work for government ministries, development partners, NGOs, or universities in the field of public health.
  • Can understand and communicate in English—the course will be conducted in English and participants will be expected to give presentations in English.
  • Have experience using Excel and have a computer that can run the latest stable release of QGIS.

The Health Data Mapping online course begins April 12 and ends July 3, 2021. Participants can expect to spend two to four hours a week working independently on self-paced lessons and completing assignments. Course facilitators will give feedback on assignments and answer questions on the course discussion forum and during periodic instructor-led virtual sessions.

The Health Data Mapping online course is ideal for those interested in learning about GIS to improve evidence-based decision making. Explore mapmaking and data analysis resources at The DHS Program Spatial Data Repository, STATcompiler, Spatial Analysis Reports, and video tutorials.

Apply now: the deadline is Monday, February 15, 2021.

The information provided on this Web site is not official U.S. Government information and does not represent the views or positions of the U.S. Agency for International Development or the U.S. Government.

The DHS Program, ICF
530 Gaither Road, Suite 500, Rockville, MD 20850
Tel: +1 (301) 407-6500 • Fax: +1 (301) 407-6501
dhsprogram.com

Anthropometry measurement (height and weight) is a core component of DHS surveys that is used to generate indicators on nutritional status. The Biomarker Questionnaire now includes questions on clothing and hairstyle interference on measurements for both women and children for improved interpretation.