Methodology
The survey used the Simple Spatial Survey Method (S3M), an area-based sampling methodology that uses settlement locations for sample selection. The survey was designed to be spatially representative of the whole country its smaller administrative units up to the locality level with the exception of few inaccessible areas .
An even distribution of primary sampling units (PSUs) (i.e., villages/city blocks) was selected from across the country. This approach was used as it is most suited to assessing indicators over wide areas to detect and map heterogeneity of indicators which is the primary objectives of this national survey (Gilbert 1987; Elliot et al. 2000; Pfeiffer 2008). PSUs (i.e. villages/city blocks) were selected based on their proximity to centroids of a hexagonal grid laid over the entire country. The resulting sample is a triangular irregular network (Pfeiffer 2008; E. H. Isaaks and Srivastava 1989). A variable density sampling approach (E. H. Isaaks and Srivastava 1989) was used to achieve a sample that draws a minimum number of PSUs from localities and from urban areas so that they can provide estimates for each of these areas with useful precision.
A sample of up to n = 32 mother and child pairs in m = 3027 PSUs was taken (see Figure 2.1). Across Sudan, a total of 93,882 households and 145,002 children below 5 years of age were surveyed.
Preparations, data collection and analysis:
Planning of the S3M II survey and in particular, the timeframe of activities, was based on the previous experience of undertaking S3M-I but also influenced the inputs of stakeholders at federal and state level, particularly members of the S3M-II technical committee at federal level, which included WHO, WFP, the Ministry of Education (MOE), the Ministry of Security and Social Welfare (MOSSW) and the Ministry of Agriculture (food security directorate), besides the Ministry of Health and UNICEF.
FMoH and UNICEF, through the S3M II technical committee, regularly engaged with key stakeholders (one to two times per week during the planning phase) and ensured their involvement in the analysis stage. All technical committee members were invited to participate in the data analysis workshops. Other stakeholders - like the Central Bureau of Statistics (CBS) were consulted and informed of the progress achieved during each of the key stages (preparation, data collection and data analysis) while stakeholders such as donors were informed of progress. In addition, in every state, state level technical committees were formed and functioned to support the planning, data collection and analysis processes. The Ethical approval request was prepared by the FMOH and submitted to the ethics committee at the research department at the FMOH. Ethical approval was granted for both S3M-II and the nested micronutrients survey from FMOH. All other relevant approvals related to undertaking the survey were obtained including visas for international consultants supporting the survey, travel permits etc. Detailed maps for all states were obtained through a successful partnership between UNICEF, FMOH and CBS. A joint workshop was undertaken in May 2018 followed by field visits in June 2018 to verify all coordinates was conducted (workshop hosted at the CBS). This was followed with a joint field visits to obtain and physically collect missing coordinates. Through UNICEF Valid International with Brixton Health were contracted and the organisations worked closely with FMOH and UNICEF throughout the survey as planned. It should be noted that the individuals included in the institutional contract were the experts who developed and later refined the S3M methodology as well as provided support to the wider Sudan team with the undertaking of the S3M-I survey in 2013. Initial list of the indicators to be included in the survey was developed through wide consultation with various sectors and stakeholders including government line ministries (MoH, MoE, MSSW, MoA) and UN agencies (UNICEF, WHO and WFP) through the S3M technical committee. The proposed list was further refined and revised by an external firm (Valid international organization) who also provided technical support throughout the survey. 226 indicators were collected and reported (see annex 1 for details).
Survey leads from UNICEF and MoH were identified and they further identified 9 UNICEF, 20 FMoH and 18 SMoH staff to supervise data collection and management. During Gezira pilot, the supervisors were trained to serve as data collectors to sharpen their skills to lead the data collection process in their respective states.. As a result, there were nine UNICEF, 20 Federal and 18 state level supervisors in addition to four supervisors from WHO who participated to oversee the collection of the micronutrient related data, as did their counterparts from the FMOH. Finally, a third-party ICT company was contracted by the FMOH to develop data collection digital tools and to provide ICT technical support and troubleshooting with regard to tablets and software issues, including presence of one ICT person in each state throughout the data collection. Sampling was carried out from 11 to 23 July 2018 by UNICEF and Ministry of Health staff in accordance with the S3M sampling methodology. This was based on the mapping of settlements across the entire country in villages and city blocks, carried out just prior to this (in 2.3.3 above), resulting in the assignment of correct GPS coordinates for more than 25,000 villages across the country.
Based on the mapping of settlements, distribution of primary sampling units was selected for each locality. This was done based on random sample selection using a sampling software designed to undertake S3M variable density sampling. The approach and selection were approved for their rigor and appropriateness by the external technical experts from Valid International. From the selected villages, consultations with state authorities including State Ministries of Health (SMOH), Humanitarian Aid Commission (HAC) and the National Intelligence and Security Service (NISS) were held to ensure the accessibility and security of villages for the survey teams and in the case of inaccessible villages, a replacement was made using the same sampling software. Further selection of households was done during the actual survey data collection; under the oversight of the external technical experts. Master training was carried-out in Gezira state (pilot state) in July-August 2018 to test tools including digital data collection tools, laboratory testing for micronutrients indicators and logistics and to train survey supervisors (through a Training of Trainers). Upon the identification of staff, all supervisors including the nine UNICEF supervisors, the four WHO supervisors, the 18 state supervisors and the 20 FMOH supervisors (including nine from Gezira state) received training from July 16 to July 25 on the following topics:
S3M-II methodology.
S3M-II questionnaire.
Digital data collection tools (tablets).
Micronutrients samples collection and storage.
TORs of all personnel and groups.
Anthropometric measurements standardisation.
S3M-II monitoring tools.
S3M-II logistic, data collection plans and quality assurance.
Local calendar.
S3M-II sampling including urban sampling.
In addition, 18 state nutrition directors received basic training on the S3M-II methodology, indicators, and the roles and responsibilities for committees involved. Further training for the supervisors for the micronutrient survey were done separately. This was followed by data collection in Gezira state which was carried-out by supervisors. Subsequent state level trainings were conducted prior to data collection for each state. Data from phase one states (North Darfur, East Darfur, West Kordofan, River Nile, Sennar, South Darfur, North Kordofan, Khartoum and Northern states) was collected in October 2018. Data from phase II states (White Nile, Kassala, Blue Nile, Central Darfur and West Darfur, Red Sea, South Kordofan and Gedaref states) was collected from November 2019 to January 2019. Close monitoring, supportive supervision and capacity-building to the Ministry of Health staff continued throughout the first phase. Technical assistance was provided from UNICEF S3M-II technical staff and Valid International throughout data collection.
