Migrant Health Follow-Up Study Wave 02 (MHFUS)
South Africa, 2019 - 2020
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MHFUS.W2.2025
Migrant Health Follow-Up Study Wave 02 (MHFUS)
| Name | Country code |
|---|---|
| South Africa | SA |
Overview of the Migrant Health Follow-Up Study (MHFUS):
The Migrant Health Follow-up Study (MHFUS) is an observational cohort study that seeks to better understand relationships between migration, urbanisation, and health in a transition setting. The MHFUS cohort includes migrants who leave the Agincourt study area in rural Mpumalanga, usually to access employment and young adult non-movers. The project also draws on the long-standing repository of personal and household data collected through by the Agincourt Health and Demographic Surveillance System (HDSS). The Agincourt HDSS has monitored the health and demographic dynamics of a population of approximately 117,000 individuals of the Bushbuckridge Municipality since 1992.
RESEARCH GOALS:
The study tracks individuals involved in temporary and circular migration and those who choose to stay in their place of origin. Its aim is to uncover how mobile individuals handle chronic diseases, access long-term care, and manage health issues (Ginsburg et al. 2021). One unique aspect is the ability to link current survey data with long-standing demographic surveillance information, providing deeper insights into the interconnected demographic and health dynamics. This approach aims to better understand the factors influencing key health outcomes. By collecting comprehensive healthcare access and treatment data, the project investigates if migration creates obstacles to care. Additionally, the research contributes to understanding migration and urbanisation by examining how migrants adapt to new environments and the impact of out-migration on rural communities.
Version
Version 1.0
Coverage
Geographic coverage and universe:
The project collects longitudinal data from a cohort of individuals within the Agincourt HDSS and other places such as Gauteng, where those who have migrated settle (Ginsburg et al. 2024; Ginsburg et al. 2021). Geographically, the Agincourt HDSS covers an area of approximately 420 square kilometres, and is located in the Bushbuckridge District, Mpumalanga in the rural northeast of South Africa close to the Mozambique border (Kahn et a. 2012).
Migrant individuals in the cohort are geographically spread across several provinces in South Africa. Most of the migrants settle within Mpumalanga and in Gauteng and then Limpopo provinces. Fewer participants live in other provinces within South Africa. Very few participants have moved outside the country.
Universe:
The recruitment of participants took place in 2017 through initial household visits (IHV). This process involved visiting the cohort participants' origin households within the Agincourt HDSS area to either locate participants residing in the HDSS household or gather contact information for those who had migrated outside of the HDSS area. During these visits, participants were asked to provide consent for future contact during the baseline data collection phase.
In the IHV round, 91.9% (N=3491) of individuals from the simple random sample frame (N=3800) were successfully tracked, and 81.3% (N=3092) were ultimately enrolled and interviewed during Wave 1. Approximately 708 individuals did not complete the baseline interview for reasons, including refusals, physical incapacitation, or being out of the age range. A small number of individuals were excluded due to being sampled twice.
A total of 74 participants were lost to follow-up in Wave 1 while, 51 participants did not complete the Wave 2 interview (see Ginsburg et al. 2024 for full enrolment and retention details). as per the MHFUS study protocol.
Producers and sponsors
| Name | Affiliation |
|---|---|
| Prof. Michael J White | Population Studies and Training Center, Department of Sociology, Brown University. Medical Research Council/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. |
| Dr. Carren Ginsburg | Medical Research Council/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. |
| Prof. Mark Collinson | Medical Research Council/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. Department of Science and Innovation/Medical Research Council, South African Population Research Infrastructure Network, South Africa |
| Prof F. Xavier Gómez-Olivé | Medical Research Council/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. |
| Prof. Steve Tollman | Medical Research Council/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. International Network for the Demographic Evaluation of Populations and Their Health Network, Accra, Ghana |
| Name | Affiliation | Role |
|---|---|---|
| Dr Chantel Pheiffer | University of Massachusetts Boston, Manning College of Nursing and Health Sciences, Department of Urban Public Health. Population Studies and Training Center, Brown University. | Researcher |
| Hong Xia | Population Studies and Training Center, Brown University. | Data Management and Analysis |
| Daniel Ohene-Kwofie | Medical Research Council/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa | Deputy Head of Data and Analytics |
| Nyiko Mathumbu | Medical Research Council/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa | Data Administrator |
| Sadson Harawa | Medical Research Council/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa | Project Manager |
| Tariro Ndoro | Medical Research Council/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa | PhD Fellow |
Sampling
Study sample, initiation and focus:
The MHFUS started in 2017, after a total of 3800 individuals aged 18 to 40 years were randomly selected from the Agincourt HDSS 2016 census (Ginsburg et al. 2021). This age group was chosen because of (1) high prevalence of temporary migration in the younger adult Agincourt HDSS population, and (2) young adults face unique health challenges and are more likely to migrate, which can impact their well-being. Hence, it is crucial to understand how migration impacts on health and health behaviours in this age group. MHFUS followed an earlier pilot study, which determined that it was possible to contacting and interview migrants both by telephone and in-person, while also pre-testing relevant survey questions (Pheiffer et al. 2019).
Survey instrument
Study questionnaires:
The repository contains data collected in Wave 2 of the MHFUS through telephone interviews. The Wave 2 questionnaire focused on socioeconomic and health dimensions, including education and employment, current residence, household membership, residence history, social capital, general health, food security and diet, tobacco and alcohol use, sedentary behaviour and sleep, and sexual partnerships.
Unlike Wave 1, Wave 2 did not include the collection of anthropometric measurements such as weight, height, waist circumference, or blood pressure. In addition, no biomarkers were collected in this wave, and Dried Blood Spots (DBS) were not obtained for laboratory analysis. This streamlined approach was designed to accommodate the telephone-based data collection method employed during Wave 2.
Additional variables in Wave 2 repository:
In Wave 2 of the study, we introduced a few new variables that were not included in the Wave 1 release. These variables were added to capture additional dimensions in Wave 2 (for example sections on mode of transportation and safety; social capital and support; medical aid and sedentary behaviour).
Data processing and quality:
Our field research operations involved a meticulous approach to ensure the accuracy and reliability of the data collected. The questionnaire data underwent on-going quality checks during fieldwork to guarantee robustness and accuracy.
Interviews responses were captured on tablets using the REDCap software. This technology enabled real-time data entry, data validation, and quality control, ensuring data integrity throughout the process.
Constructed variables:This Wave 2 data repository release encompasses variables collected during the Wave 2 interview (prefixed w2) and constructed variables (prefixed either c1 or c2).
Variables with the prefix "c1 or c2" are constructed or derived variables which involve combinations, transformations, aggregations or recodes of one or multiple "w2" variables. These constructed variables present more nuanced or summarised information to aid in analysis.
-
Constructed variable for person weight
c2_fwk_peweight This variable allows the user to introduce weights into analyses that adjust for differential participation of sampled individuals in Wave 2 -
Constructed variable for successfully interviewed participants
W2_ResponseSuccess This variable with 3018 observations, relates to the response success of the Wave 2 survey interview. -
Constructed variable related to geographic location
Explanation about village of origin and current residence
• Origin village: Refers to the (anonymised) village within the Agincourt HDSS where the participants origin households are located. Currently, the Agincourt HDSS has 31 villages.
• Denotes the current location where the participant resides, which may be within or outside the Agincourt HDSS.
c2_pre_origin_cat Represents participant’s village of origin that has been anonym
c2_res_current_cat Represents the participants current place of residence at an aggregated provincial level. It further distinguished participants resident in the HDSS study site (in Mpumalanga) from participants residing in other parts of the Mpumalanga province. The category “other” includes participants in Limpopo, North West, KwaZulu-Natal, Free State, Eastern Cape, Western Cape and Northern Cape.
c2_migrant W2 Migrant status (classified as either HDSS resident (non-migrant) or migrant at the time of the Wave 2 interview). -
Constructed variable for participant date of birth and interview date
Below are constructed variables for participants date of birth and date of interview
c2_fwk_int_d Day of W2 interview
c2_fwk_int_m Month of Wave 2 interview
c2_fwk_int_y Year of Wave 2 interview
c2_pre_dob_y Year of birth of the participant
c2_pre_age Age of the participant on the date of the Wave 2 interview -
Constructed variables extracted from household roster:
Variable name Explanation
W2_res_hhkids Represents the count of household members under 18 years old. Invalid missing values have been replaced to ensure consistency with the household roster.
W2_res_hhadults Represents the count of household members aged 18 or older, excluding the respondent.
W2_res_sizecalc Represents the total household size, including all children, adults, and the respondent.
These variables have been cleaned replacing some invalid missing vales and ensuring alignment with the total household members reported.
Commitment to transparent and ethical data exploration
As custodians of these data, we are committed to facilitating transparent, ethical, and insightful exploration. We hope that this release fosters innovation, encourages collaboration, and yields meaningful discoveries on questions concerning internal migration and health.
Further information on the Migrant Health Follow-Up Study can be found at: https://sites.brown.edu/migration-and-health/
For further information on the data release, please contact the MRC/Wits Agincourt data team (DataRequest@agincourt.co.za) . Please submit any customised data requests using the link: https://data.agincourt.co.za/index.php/auth/login/?destination=access_custom_request
Acknowledgement
This work was supported by US National Institutes of Health Grant [grant number 1R01HD083374],“Migration, Urbanization and Health in a Transition Setting.” (PI: M. White) and institutional support to Brown’s Population Studies and Training Center supported by National Institutes of Health [grant number P2CHD041020] (https://www.nih.gov/). The MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt) acknowledges funding from The Wellcome Trust, UK [grant numbers 058893/Z/99/A, 069683/Z/02/Z, 085477/Z/08/Z, 085477/B/08/Z] (https://wellcome.ac.uk/), and the Medical Research Council, South Africa
References for key papers
Please find below references to key papers in which we cite the background study and the pilot of the MHFUS study:
- Ginsburg, C., Collinson, M.A., Pheiffer, C.F., Gómez-Olivé, F.X., Harawa, S., McGarvey, S.T., Ohene-Kwofie, D., Foster, A.D., Myroniuk, T.W., Lurie, M.N. and Tollman, S.M. (2024). Cohort Profile: Migrant Health Follow-Up Study (MHFUS) of internal migration in South Africa. International Journal of Epidemiology, 53(4).
- Ginsburg, C., Collinson, M.A., Gómez-Olivé, F.X., Gross, M., Harawa, S., Lurie, M., Mukondwa, K., Pheiffer, C.F., Tollman, S., Wang, R., & White, M.J. (2021). Internal migration and health in South Africa: Determinants of healthcare utilisation in a young adult cohort. BMC Public Health, 21:554.
- Kahn, K., Collinson, M.A., Gómez-Olivé, F.X., et al. (2012). Profile: Agincourt Health and socio-Demographic Surveillance System. International Journal of Epidemiology, 41(4), 988-1001.
- Pheiffer, C.F., McGarvey, S.T., Ginsburg, C., Collinson, M., Gómez-Olivé, F.X., Tollman, S., & White, M.J. (2019). Dimensions of internal migration and their relationship to blood pressure in South Africa. Journal of Biosocial Science, 51(6), 827-842.
Data collection
| Start | End | Cycle |
|---|---|---|
| 2019 | 2020 | 4 Months |
| Start date | End date |
|---|---|
| February 2019 | January 2020 |
- Interviewer-administered
Data collection and ethics:
This release contains data from Wave 2 of the MHFUS, future releases will include data from Waves 3 and 4. Waves 1 and 4 involved in-person visits, collecting biometric measures and detailed information on sociodemographic factors, health and health behaviours. The study follows a sample of 3092 individuals some of whom migrate and others who remain in the Agincourt HDSS study site, observing migration patterns and associated health and socioeconomic factors. The research is unique in that it tracks and collects data directly from migrants and Agincourt residents in the cohort through face-to-face and telephone interviews.
Data were collected from cohort participants, after informed consent was obtained by trained fieldworkers. Respondents were informed of the purpose of the study and confidentiality of the interview, their right to refuse participation or withdraw from the study, and that scientists would be given access to anonymised data to analyse and publish information. For those who consented to participate, they were also informed of their right to refuse to answer some questions, part of the question or biomarkers.
The Migrant Health Follow-Up Study was granted ethics clearance by the University of the Witwatersrand Human Research Ethics Committee (Medical) (clearance certificate numbers M170277 and M220160) and the Mpumalanga Province Department of Health Research and Ethics Committee.
Contacts
| Name | Affiliation | |
|---|---|---|
| Dr. Carren Ginsburg | Medical Research Council/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. | Carren.Ginsburg@wits.ac.za |
Metadata production
MHFUS.W2.2025