Baseline Mapping — Establish the Baseline Population and Maps of Geographic Clusters
Step 9
Before birth and death surveillance begins in each cluster, it is importance to create maps and enumerate the population of each study cluster.
Mapping Clusters
A team of cartographers should visit all clusters to create a digital map of each cluster and obtain their geocoordinates. If the sampling frame of census enumeration areas (EA) are used, it is likely that sketch maps of each EA are already available from the national statistics office (NSO). These may be obtained and used as an aid in the redefinition of the clusters’ boundaries. It is essential to work with cartography experts from the NSO, who should lead the training to the mapping teams. In general, two individuals will be sufficient to map each cluster within 2-3 days.
For each EA, the boundaries are delimited by tracking all the boundaries using a motorcycle and taking the GIS coordinates for each corner, using a tablet computer. Then all households located within the EA are visited to allocate a household identification number and collect the name of the head of the household and the total number of people living in the household, and the geocoordinates. If there are multiple EAs that form a cluster, all EAs within the same cluster are mapped using the same procedure.
Two main issues frequently arise during the cartography. The first concerns largely populated clusters, such as those with more than 300 households, and the second concerns clusters that split across a standalone community with no visibly clear boundaries. These cases must be carefully discussed and decided upon, with the decision incorporated into the training of the mapping team. In the first case, the cluster may be split and only one portion (with reasonable number of households) mapped. This process of splitting large clusters must be done, and a portion must be randomly selected before the mapping team goes to the field. However, the realities and practicalities of the ground must also be considered, including population distribution and accessibility. For the second issue, adjustments to the cluster boundaries can be made to ensure that the cluster is physically well bounded and risk of surveillance outside the cluster is minimized.
After the mapping fieldwork, clusters and EAs maps are created. Household locations can be plotted on the maps. The maps will later be printed and provided to community workers and data collection teams.
Baseline Household and Population
After the cartography activities, community workers and their supervisors, the VASA interviewers, use the maps and household lists to revisit every household in the cluster to collect detailed information on each household member and the household using tablets or mobile phone loaded the household listing questionnaire. A household is defined as a person or group of related or unrelated persons who live together in the same dwelling unit(s), who acknowledge one adult male or female as the head of the household, who share the same housekeeping arrangements, and who are considered a single unit. Each country has its own definition of a household, which may vary slightly from this definition, but generally, the definition is very similar.
The data collectors request the permission of the head of the household to participate in the study by using the household consent form document. They should clearly inform the head of the household that subsequent visits will follow in case of any event or the monthly/bimonthly household visit. They conduct the baseline interview, which involves interviewing the head of the household or any adult member that can provide information on each member of the household (full names including surnames, age, sex, education, and marital status, etc.). They may also collect information about the household’s durable assets. It is recommended that the mapping and household listing be updated every 2-3 years.
The household listing exercise provides an opportunity to introduce the community worker to each household and get buy-in and support from the community. It is therefore essential that the community worker is fully involved in the activity. A list of households with their ID will later be printed and provided to the community worker as an aid for the community surveillance.
During the first household visit, data collectors also record information about any pregnancies, births and deaths that have occurred in the household during the past three months. Active community surveillance of vital events should start after the listing is completed.
Baseline Supervision and Quality Assurance
During the household listing phase, supervisors visit a sample of households, repeat the interview process, and compare the data to that collected by the community data collectors. The data collectors are then provided with feedback, and where necessary, are retrained on data collection procedures.
Scaling Up Data Collection
During the planning phase, the project leaders should carefully discuss the best strategies to scale up the project, taking into consideration geographic and cultural challenges as well as country health priorities. A phased or stepwise implementation roll-out is highly recommended, meaning that the project is first implemented in a subgroup of geographic areas, rather than nationwide. This approach is essential to increase the likelihood of successful implementation and to allow faster learning for roll-out.