The Agincourt Health and Population Unit (AHPU) is an educational and research unit located within the School of Public Health at the University of the Witwatersrand, South Africa. Since 1992, AHPU has been collecting information on birth, death and migration for all individuals identified as members of the approximately 11,700 households under surveillance in a rural sub-district in (what is now) Mpumalanga Province, South Africa. (For more information on the Agincourt Unit, see http://web.wits.ac.za/Academic/Health/PublicHealth/Agincourt/ .) The area is home to South Africans and Mozambicans, the latter group settling here legally during the civil war in Mozambique. Most Mozambicans here have permanent residency status which, according to the South African Constitutional Court, allows them access to government transfers. However, it is more difficult for Mozambicans to access government grants, largely because they lack the documents necessary to do so.
In 2002 a study team collected data in Limpopo Province, at the Agincourt Demographic Surveillance Site, through the auspices of Philani Nutrition and Development Project. The work was funded by the National Institute on Aging under grant numbers R01 AG20275-01, P01 AG05842-14, and P30 AG024361. The project used this integrated health and economic survey in South Africa to investigate the links between health status and economic status. The survey instruments collected data on a range of traditional and non-traditional measures of well-being including income and consumption, measures of health status (including mental health), morbidity, crime, social connectedness, intra-household relationships, and direct hedonic measures of well-being. Random household selection was stratified by age-eligibility for Old Age Pension and nationality. In 2004 there was a second cross-sectional study conducted in Agincourt. A random selection of households was stratified on the basis of (a) citizenship, (South African or Mozambican),(b) and whether or not a death had occurred in the household.
Kind of Data
Sample survey data
Unit of Analysis
Households and individuals
v1: Edited, anonymised dataset for public distribution
Income and consumption, measures of health status (including mental health), morbidity, crime, social connectedness, intra-household relationships, and direct hedonic measures of well-being
The survey covered a rural sub-district in Mpumalanga Province, South Africa
The lowest level of geographical aggregation is villages.
The Agincourt Integrated Family Survey 2002 covered all household residents, Woman aged 60 and above and men aged 65 and above in the household
Producers and sponsors
Professor Anne Case
National Institute on Aging
Sample selection for the Agincourt Integrated Family Survey involved extracting a sample of households, stratified by age-eligibility for the Old Age Pension and nationality. Age eligibility is defined as having either a woman aged 60 and older or a man aged 65 and older in the household.
The frame from which the sampling was provided by the 2001 census round of the Agincourt demographic surveillance system.
The sampling design for Agincourt 2002 had the following characteristics:
1. The villages within the population were stratified into two: a set of "Mozambican villages" and a set of "South African" ones.
2. 11 villages were selected, 4 "Mozambican" and 7 "South African" ones. Villages were selected with probability proportional to number of households.
3. The households within each village were assigned to two strata: age-eligible households and non-age-eligible ones.
4. Within each selected Mozambican village twenty households were selected at random, ten from each stratum. In each South African village, thirty household were selected, twelve from the "age-eligible" stratum and eighteen from the "non-age-eligible" stratum.
The final sampling design was:
Strata SA villages Mozambican villages
age-eligible 84 40
not age-eligible 126 40
The project did not explicitly stratify on nationality, but did so implicitly via the villages. This was not only because of limited confidence in the "nationality" identifiers, but also because a clustered design seemed advisable in any event. Clustering was decided on because it would make the logistics of fieldwork easier and because cluster effects might be interesting in their own right. Location is related both to social factors ("Mozambican" villages are somewhat stigmatized) and to geographical ones (there are differences in microclimates and hence crop patterns and also in access to infrastructure). The design ensured that there were at least twenty households in each cluster which should ensure that some of these cluster effects could be taken into account. The final sample size was 290 households.
The sampling frame for the selection of the villages:
The Agincourt Demographic Surveillance System has information on 21 villages. These formed the initial population from which the sample was drawn. Prior to sampling four villages were excluded from consideration:
(1) The RDP Housing project - The reason for excluding this settlement was that the dwelling units are apparently not a "household" in the sense in which the project wanted to investigate. Apparently many households send one or two junior members to occupy the RDP house (to maintain a claim to the property), but most of the household activities remain centered on dwellings elsewhere within the study site. It seemed sensible, therefore, to exclude the housing project from consideration.
(2) Ireagh A, Ireagh B and Kildare A - The project team were requested by Mark Collinson, the fieldwork manager of the Agincourt Health and Population Unit, not to include these villages in the sample, since other studies would be run (or were currently running) in these villages. The grounds for exclusion were that overstressing villages might contaminate the field results from the studies and might make fieldwork in future studies more difficult.
There were no visible differences between the excluded villages and the other "South African" villages that did not fall within the range of sampling variability.
Stratification within villages by age-eligibility and selection of households:
All households within the selected villages were assigned to one of two strata: age-eligible and non-age-eligible. This was done on the basis of the information available in the data base. Age eligibility was calculated as at the 23rd January 2002 (the date on which the sampling was done). Sampling within each of the strata was done by means of simple random sampling, without replacement.
The overall inclusion probabilities of households in each of the strata, and hence the appropriate inflation factor was calculated by combining the village selection probabilities with the conditional selection probabilities. This was carried out for the project by Professor Martin Wittenberg at the University of Cape Town. These inflation factors are included in the household dataset under the name "Hweight."
Dates of Data Collection
Data Collection Mode
The most knowledgeable household member (khhm) was the initial person interviewed within the household. He or she would list all of the members of the household. This list of household members was then used as a guide for the entire interview process. The khhm first answered questions about the individual members of the household: age, gender, education, marital status, is that person?s partner in the household, is that person?s parent in the household. Additionally, the khhm was asked about the source and amount of income of each household member.
Summary information was gathered from the khhm about the household members who had died and the household members who had moved. In study years starting in 2003, detailed questions were posed about the effect the most recent death had on the household.
Detailed questions were asked of the khhm about the living conditions: access to toilet facilities and running water, a stove, a phone. Questions about household expenditure were asked
In 2002, there were two separate adult questionnaires. One questionnaire was for adults whose ages fell between 18 and 54; the second questionnaire was for adults 55 years old and up. In subsequent study years there was one questionnaire for adults 18 and older. Every adult from the household, who was available and willing to, answered these questions. Questions about age, marital status, number of living children, and number of children who have died were included. Detailed questions were asked about their sources of income and their expenditures. For older adults, there were questions about pensions and grants, for mothers there were questions about childcare grants. Individuals described the type of jobs they held over the years, how much money they earned and how they spent that money. Detailed health questions were posed; both physical and mental health issues were covered. Physical measurements were taken of the individuals interviewed: their height, weight, waist size; blood pressure and pulse.
The parent or guardian of each child was questioned about the child. Questions included those on birth weight, history of breastfeeding and health of the child. With the parent's or guardian's permission the child?s height and weight were measured. Detailed information was recorded about the child?s immunization history.