GIS BROCHURE

Guidance on how to use Geographic Information

A Field Guide to GPS Data Collection

MEASURE DHS GPS Data Format (pdf, 83 KB)

Online GIS tools for non-GIS users
STATcompiler allows users to create interactive maps of hundreds of indicators from DHS surveys.

Online GIS tools for GIS users
HIV Spatial Data Repository provides geographically linked, HIV-related data for mapping in a GIS for 49 countries. Data are provided in shape files that allow GIS users to integrate their own GIS data with the DHS HIV/AIDS indicators data.

Geographic location affects peoples' health, nutrition, and access to health care services. The MEASURE DHS project can now analyze the impact of location using DHS data and geographic information systems (GIS). These spatial analyses improve our understanding of how location affects health status, leading to more effective interventions.

MEASURE DHS routinely collects geographic information in all surveyed countries. Using GIS, researchers can link DHS data with routine health data, health facility locations, local infrastructure such as roads and rivers, and environmental conditions. Linked DHS and geographic data are now being used to improve planning for family planning interventions, to assess the correlation of malaria prevalence and anemia in children in West Africa, and to analyze the effects of environment on early childhood mortality.

MEASURE DHS is a recognized leader in training local interviewers to collect geographic information. For both DHS and Service Provision Assessment surveys (SPA), local researchers are trained to use hand-held Global Positioning System units to collect latitude and longitude coordinates in the field. These coordinates indicate the location of surveyed communities and/or health facilities. The GPS data collection standards and manual prepared by MEASURE DHS are now being used for the World Bank's Living Standards and Measurement studies and the World Health Organization's World Health Surveys. UNICEF has also adapted the DHS manual for their Multiple Indicator Cluster Surveys in the upcoming round of data collection.

Methodology - Collecting Geographic Data

Two types of geographic information are included in the DHS and AIS surveys. All survey data is presented both nationally and by sub-national reporting area. These reporting areas are often, but not always, provinces or groups of provinces, and are included in all recoded data files.

In most recent DHS surveys, the location of communities that participated in the survey is geo referenced using a GPS receiver. Data on the location of these communities, or clusters, is released as a separate DHS data file. More detailed information on the survey cluster coordinate data is given below.

Survey cluster coordinates are collected in the field using GPS receivers, usually during the survey sample listing process. The collected coordinates are always checked for accuracy before they are released to the public. The source of the coordinates (GPS, map, gazetteer) is reported in the geographic data file that is released to the public.

The precision of the data is also affected by the quality of the GPS units and the environmental conditions at the cluster location. In general, the coordinates reported in most surveys are accurate to approximately less than 15-20 meters.

In order to ensure that respondent confidentiality is maintained, we now randomly displace the GPS latitude/longitude positions for all surveys.   The displacement is randomly carried out so that rural clusters contain a minimum of 0 and a maximum of 5 kilometers of positional error. Urban clusters contain a minimum of 0 and a maximum of 2 kilometers of error. A further 1% of the rural clusters are displaced a minimum of 0 and a maximum of 10 kilometers.