Africa Centre for Population Health has built up, since January 2000, an extensive longitudinal database of demographic, social, economic, clinical and laboratory information about the members of its demographic surveillance area (DSA), which is situated in a rural area of northern Kwa-Zulu Natal.
The database integrates data collected from the three research platforms. The population research platform produces longitudinal data on households and individual members of households. These data include episodes of residence at geo-located dwellings and vital events such as birth, death (including cause of death based on verbal autopsies), migration and marriage. Socio-economic data, education and employment are collected annually from households and individuals. An annual interview with each individual aged 15 years and older collects behavioural and health service utilisation data. A dried blood spot is collected at this interview on which a number of bio-measures are done, including HIV sero-status, HIV viral load, HIV and TB pathogen sequencing of selected samples, and HbA1c. The data from research studies conducted on the population platform are linked to the core longitudinal population data through a unique individual identifier and integrated into a shared longitudinal database. A good introduction to the data, plus references to numerous publications using the data is available here. Click here to understand the operational model for demographic surveillance.
The clinical research platform obtains routine health care data (e.g. anti-retroviral treatment records, TB registers) and all routine laboratory investigation results in electronic form from the local public health care providers. The data is consolidated in a clinical database and is linked on an ongoing basis to the population database. Data from clinical studies are integrated into the clinical database.
The laboratory platform uses a laboratory information management system (LIMS) to register, track, record analytical results and locate samples in the biobank. Specimen identifiers are linked to individual identifiers in the population and clinical databases and laboratory results integrated with the data in these database.
From the integrated database, Africa Centre has developed a suite of analytical data sets which can be used both by affiliated scientists, and by other researchers. Standard analytical datasets which include core, demography, general health, HIV and household socioeconomic data are generated, documented and archived on the Africa Centre data repository twice yearly. Questionnaires used for data collection are also included as part of the dataset documentation. To protect participant privacy and confidentiality, individual and household identifiers are anonymised. Datasets archived on the data repository are encrypted such that datasets from two different studies cannot be linked to one another. These datasets can only be linked using a mapping table which contains anonymised identifier and a common identifier. The mapping table is archived on the data repository and has restricted access. A data user needs to submit an online request to access the table and approval is granted where a good justification is given to link the data sets.