ALPHA data come from different sources, including demographic surveillance, verbal autopsy interviews, serological and sexual behaviour surveys, and individually-linked data from medical facilities. The micro data are organised in different data tables or data specifications and briefly described below. The numbering of the various specs has historically grown and has no specific meaning. More detailed descriptions of ALPHA metadata can be found here.
Data spec 6.1: Residency episodes
Data spec 6.1 is the basis for most analyses and is used to compute person-year denominators for age-specific rates. In addition, it contains information on the events (e.g., births, deaths, migrations) that initiate or terminate residency episodes. There is one record per residency episode for each individual in the dataset that is sourced from the demographic surveillance. Individuals who have been continuously resident in the same household between first and last date of observation will have only one record; individuals who moved household within the demographic surveillance area, or, have left and returned to the area since the time they were first seen, will have two or more records.
Data spec 6.2b: HIV test data
Data spec 6.2b contains the information for classifying individuals by HIV status, and track how this changes over time. Spec 6.2b has one record for every recorded or reported HIV test in the study or clinic data.
Data spec 7.1: Mother and father identifiers
Data specs 7.1 contains the parental information whenever possible for all children/adolescents and also any parental links for adults if you have them. Mothers/fathers in the study area are supposed to have all their children linked in Data spec 7.1.
Data spec 7.2: Reported births
Data specs 7.2 contains for females only, one record for each birth reported by all mothers in DSS.
Data spec 7.4: Survey information – background characteristics
Data specs 7.4 contains background characteristics for each individual (Men and women of all ages), one record for each Survey interview (DSS and Sero). This spec contains only information that was given from direct questions and not derived from other tables. For example mother status only comes from the individuals data not derived by linking the mother to the individual.
Data spec 8: Verbal autopsy data
Spec 8 contains the data from interviews with caretakers from deceased residents about the circumstances of the death and the signs and symptoms suffered by the deceased in the illness episode leading up to the death. Spec 8 contains one record per deceased resident. All ALPHA Network member sites use verbal autopsy questionnaires that are based on the WHO Verbal Autopsy standards.
Data spec 9.1: self reported data on HIV care and treatment services
Spec 9.1 contains self reported data on HIV services use; it contains one record per report.
Data spec 9.2: HIV care clinic data
Spec 9.2 contains information on HIV care from linked clinic data. These are usually, but not exclusively, facilities providing antiretroviral therapy. Spec 9.2 contains one record per individual per clinic visit.