AHRI HDSS:Individual Health Surveillance HIV All

The Africa Centre Demographic Information System (ACDIS) was established in 2000 by the Africa Health Research Institute (AHRI; formerly the Africa Centre for Health and Population Studies) covering a population of approximately 85,0000 residents and non-residents from an area 438km2 in size in uMkhanyakude district, KwaZulu-Natal province, South Africa. In 2017, this area was expanded to 845km2 and renamed to Population Intervention Programme (PIP) with approximately 140,000 individuals in 20,000 households (as of 2018) which included communities of a cluster randomized trial of HIV treatment. In 2017 the surveillance system was incorporated into the South African Population Research Infrastructure Network (SAPRIN) and is now known as the AHRI HDSS (Health and demographic surveillance system). A sea change in the research operations has been implemented from 2017 and include the following:

· Capturing questionnaire data electronically, and addition and modification of the survey questions. Questionnaires are administered on tablet computers using the Research Electronic Data Capture (REDCap) system. Sexual behaviour and other sensitive questions are collected by computer-assisted self-interview. Questions have been added to the household survey on receipt of government grants, food security and experience of violence. The verbal autopsy (VA) questionnaire (administered routinely for all deaths) has been updated to conform to WHO 2016 and later the 2020 standards. In the individual survey, questions have been added about diagnoses and treatment of HIV, TB, hypertension and diabetes, and old questions dropped. Most recently (April 2020), COVID-19 surveillance has been introduced.

· Offering home-based HIV counselling and testing (HCT) during the survey visit. At the annual home visit, all resident household members aged =15 years who are not on ART are offered HCT, even if they do not participate in the survey. Individuals who test positive and not currently on ART are referred to HIV care at a clinic in the surveillance area. They are also asked to consent to facilitated linkage through AHRI's new AHRILink system.

· Capturing of clinic attendance in the PIP area. AHRI implemented the AHRILink system in 2017, to collect the date and reason for attendance of all individuals who attend one of the 11 clinics in the PIP study area. Consenting individuals who are referred to care after HCT, or other screening tests, and do not attend a clinic within 10 days are sent a reminder text message; those who have still not attended within 30 days are contacted by telephone by a trained counsellor and encouraged to attend for care.

Between 2003 and 2016, the annual Individual Health surveillance involved drawing, at the start of each data collection surveillance round, an “Eligibility List” of all adult eligible individuals, and then, during the data collection round, attempting to contact those individuals. From 2017, the approach has changed, and the eligibility list is drawn at the start of the data collection week. Inevitably, some will have died, moved away, become very sick etc. even before the Eligibility List is drawn (since we only contact households three times per year, two contacts are through the call centre and one contact is through a physical visit to the homestead). Eligibility criteria for inclusion into the Eligibility List has changed over the years. Between 2003 and 2011, residents' males aged 15 and 54 and resident females aged 15 and 49 were included. A 10% stratified sample of non-residents was also included. From 2012, all resident individuals aged 15 years and above are included.

Note: The data user is encouraged to read the data documentation for each individual dataset to understand the Eligibility Criteria which was used in each of the survey data collection rounds.

Individuals are free to refuse to participate in and to withdraw from the individual component, without any impact on routine health care or other services to which they are entitled. If a household refuses to participate in the household component, its members will not be invited to participate in the individual component during that same household visit. Residents wishing to participate in the individual surveys will be able to independently access the mobile clinics, where the informed consent process and all individual-level study procedures are conducted.

While the annual HIV surveillance datasets include everyone in the Eligibility Lists, the overall HIV dataset, Women General Health and Men General Health only include those individuals who were contacted to the extent that they themselves could be asked whether or not they wanted to participate. Note, though, that cases where contact is made, but the individual or head of Household etc, then refuse to participate are included in the women General Health and Men's General Health datasets. The records will have RefusedAll = Y.

Users of these datasets are strongly encouraged to refer to the questionnaires included in the documentation for the annual datasets to check carefully for any changes in question wording, ordering, options offered etc. This document does not attempt to describe every single change and variation.