title: "The difference that makes a difference": highlighting the role of variable contexts within an HIV Prevention Community Randomised Trial (HPTN 071/PopART) in 21 study communities in Zambia and South Africa.
abstract: This paper explores contextual heterogeneity within a community randomised trial HPTN 071 (Population Effects of Antiretroviral Treatment to Reduce HIV Transmission) carried out in 21 study communities (12 Zambian, 9 South African). The trial evaluates the impact of a combination HIV prevention package (including household-based HIV counselling and testing and anti-retroviral treatment (ART) eligibility regardless of CD4-count) on HIV incidence. The selection, matching and randomisation of study communities relied on key epidemiological and demographic variables and community and stakeholder support. In 2013, following the selection of study communities, a "Broad Brush Survey" (BBS) approach was used to rapidly gather qualitative data on each study community, prior to the implementation of the trial intervention. First-year process indicator intervention data (2014-2015) were collected during the household-based intervention by community lay workers. Using an open/closed typology of urban communities (indicating more or less heterogeneity), this qualitative inquiry presents key features of 12 Zambian communities using a list of four meta-indicators (physical features, social organisation, networks and community narratives). These indicators are then compared with four intervention process indicators in a smaller set of four study communities. The process indicators selected for this analysis indicate response to the intervention (uptake) amongst adults. The BBS qualitative data are used to interpret patterns of similarity and variability in the process indicators across four communities. We found that meta-indicators of local context helped to interpret patterns of similarity and variability emerging across and within the four communities. Features especially significant for influencing heterogeneity in process indicators include proportion of middle-class residents, proximity to neighbouring communities and town centre, the scale of the informal economy, livelihood-linked mobility, presence of HIV stakeholders over time and commitment to community action. Future interdisciplinary analysis is needed to explore if these patterns of difference continue to hold up over the full intervention period and all intervention communities.
authors.affiliation: a Zambart Project, University of Zambia, School of Medicine , Lusaka , Zambia.|b Department of Global Health and Development, Faculty of Public Health and Policy , London School of Hygiene and Tropical Medicine , London , UK.
authors.forename: Virginia
authors.initials: V
authors.lastname: Bond
authors.affiliation: a Zambart Project, University of Zambia, School of Medicine , Lusaka , Zambia.
authors.forename: Bwalya
authors.initials: B
authors.lastname: Chiti
authors.affiliation: c Desmond Tutu TB Centre, Department of Paediatrics and Child Health , University of Stellenbosch , Cape Town , South Africa.
authors.forename: Graeme
authors.initials: G
authors.lastname: Hoddinott
authors.affiliation: d Department of Sociology and Social Anthropology , Stellenbosch University , Matieland , South Africa.|e Population Studies and Training Center , Brown University , Providence , RI , USA.
authors.forename: Lindsey
authors.initials: L
authors.lastname: Reynolds
authors.affiliation: a Zambart Project, University of Zambia, School of Medicine , Lusaka , Zambia.|f Department of Infectious Disease Epidemiology , London School of Hygiene and Tropical Medicine , London , UK.
authors.forename: Ab
authors.initials: A
authors.lastname: Schaap
authors.affiliation: a Zambart Project, University of Zambia, School of Medicine , Lusaka , Zambia.
authors.forename: Melvin
authors.initials: M
authors.lastname: Simuyaba
authors.affiliation: a Zambart Project, University of Zambia, School of Medicine , Lusaka , Zambia.
authors.forename: Rhoda
authors.initials: R
authors.lastname: Ndubani
authors.affiliation: c Desmond Tutu TB Centre, Department of Paediatrics and Child Health , University of Stellenbosch , Cape Town , South Africa.
authors.forename: Lario
authors.initials: L
authors.lastname: Viljoen
authors.affiliation: a Zambart Project, University of Zambia, School of Medicine , Lusaka , Zambia.
authors.forename: Musonda
authors.initials: M
authors.lastname: Simwinga
authors.affiliation: g Department of Medicine , Imperial College London , London , UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Fidler
authors.affiliation: f Department of Infectious Disease Epidemiology , London School of Hygiene and Tropical Medicine , London , UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Hayes
authors.affiliation: a Zambart Project, University of Zambia, School of Medicine , Lusaka , Zambia.|h Department of Clinical Research , London School of Hygiene and Tropical Medicine , London , UK.
authors.forename: Helen
authors.initials: H
authors.lastname: Ayles
authors.affiliation: b Department of Global Health and Development, Faculty of Public Health and Policy , London School of Hygiene and Tropical Medicine , London , UK.|i MRC/UVRI Uganda Research Unit on AIDS , Entebbe , Uganda.
authors.forename: Janet
authors.initials: J
authors.lastname: Seeley
mesh_terms: D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D055812:Community-Based Participatory Research; D003376:Counseling; D015658:HIV Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D015994:Incidence; D008297:Male; D012111:Residence Characteristics; D013019:South Africa / Q000453:epidemiology; D015024:Zambia / Q000453:epidemiology
chemical_list: D044966:Anti-Retroviral Agents
keywords: Context; HIV intervention; Zambia; community randomised trial; heterogeneity; variability