The home based HIV counselling and testing study was undertaken in the rural uMzimkhulu subdistrict of Sisonke district, KwaZulu-Natal province, South Africa. This subdistrict is in one of the poorest areas in South Africa, where 77% of households live below the poverty line. The area is characterised by dispersed rural settlements with minimum economic activity, and out-migration to urban centres for work is common.13
A large proportion of households are headed by women.13
Antenatal HIV prevalence in the Sisonke district is 37%, placing it within the 10 highest HIV prevalence districts in the country.14
We undertook a cluster randomised controlled trial to assess the effect of home based HIV counselling and testing on the primary outcome, prevalence of testing for HIV. Secondary outcomes included HIV awareness, stigma, sexual behaviour, vulnerability to violence, and access to care. We randomly assigned clusters rather than individuals, thereby avoiding the potential contamination between intervention and control groups and more accurately following the approach that would be taken at scale.
To limit the risk of contamination between clusters we used census data from Statistics South Africa to demarcate clusters with similar estimated population sizes and suitable borders or natural boundaries (such as roads, rivers, and hills). We undertook a cross sectional baseline household survey in all 16 identified clusters between September and November 2008. Trained data collectors conducted a door to door survey of all adults in the households to collect information on characteristics needed for randomisation: sociodemographic characteristics and history and location of previous HIV testing.15
No stratification or matching was deemed necessary based on the results from the baseline survey, and we included all 16 clusters for randomisation. We used simple computer generated randomisation with clusters assigned in a 1:1 allocation ratio (see supplementary figure). Data collectors who undertook the post-intervention survey were different staff from the team implementing the intervention and were masked to the allocation assignment—that is, they were not informed about the cluster allocation.
Home based HIV counselling and testing intervention
In collaboration with the Sisonke district department of health we developed the home based HIV counselling and testing intervention whereby local women selected from within the intervention clusters were trained as lay counsellors. Only female counsellors were included in this rural area, after consultation with the village chiefs, because it would not have been deemed culturally appropriate for men to counsel women without their husband present and this area is largely headed by women as most men migrate for work. Selection criteria for lay counsellors included completion of 12 years of schooling, residence in the intervention area, and a history of community work.
The intervention team included a clinical nurse supervisor, 11 lay counsellors (three clusters had two counsellors each owing to the distances between households), and four intervention supervisors, who were all from the subdistrict and spoke the local language, a mixed dialect of Zulu and Xhosa. All staff completed a 10 day nationally accredited course in HIV counselling and testing, and the counsellors spent four months being supervised in local health facilities to gain experience of testing.
At the start of the intervention a period of extensive community mobilisation took place. This involved the counsellors having discussions with local chiefs and traditional leaders about HIV and HIV counselling and testing. Through these discussions the community leaders were encouraged to be the first in their communities to be tested. Counsellors also arranged slots to have discussions about HIV and HIV counselling and testing at regular chief gatherings (imbizos), women’s meetings, and pension days, where leaders and counsellors discussed the importance of HIV counselling and testing.
From September 2009 to November 2010, the lay counsellors carried out door to door visits of all households in the designated intervention clusters. After seeking permission from the household head, the lay counsellors offered free pretest counselling, HIV testing, and post-test counselling to all household members aged 18 years and older. Adolescents aged 14-17 years were also offered testing provided they had parental or guardian consent in accordance with national guidelines. Counsellors were trained to encourage couples counselling and testing.
Lay counsellors gave basic education on HIV/AIDS, after which clients were allowed to make a choice regarding participation. Those who volunteered to participate were then met individually (or as couples) in a private room or section of the home, where pretest counselling, HIV testing, and post-test counselling took place.
The counsellors used the same rapid HIV test kits that were used by district health facilities during the study period: SD Bioline (Standard Diagnostics, Korea) for screening, and SENSA Tri-line (Hitech Healthcare, China) for confirmation of HIV positive test results. Those who tested positive were given a referral letter to be taken to a local healthcare facility of their choice for CD4 testing and other HIV related services. HIV positive clients were also contacted approximately twice by their counsellor after diagnosis to assess progress and access to needed health and social services.
Standard care was available in control clusters, which consisted of HIV counselling and testing services at local clinics and some non-governmental organisation mobile outreach teams. HIV testing in clinics is also generally undertaken by lay counsellors, although it may be undertaken by nurses if no lay counsellors exist. Midway through the study, in 2010, a national HIV counselling and testing campaign was launched by the minister of health.16
The campaign aimed to promote HIV testing in clinics and government hospitals and in mobile units going from clinics into communities. Home based testing was not part of the campaign. The target was to test 15 million South Africans by June 2011. This cointervention took place in the subdistrict where our trial was based; however, after discussions with the district it was decided that the campaign would only be implemented in the control communities since our intervention was already delivering HIV counselling and testing services in the intervention communities and would contribute to the district campaign targets. No radio or other mass media was used to communicate about the campaign.
A household survey was undertaken between February and May 2011 in the 16 randomised clusters, approximately 18 months after the start of the intervention, to measure primary and secondary study outcomes. The primary outcome was collected at baseline and post-intervention, whereas the secondary outcomes were only collected in the post-intervention survey. No longitudinal follow-up took place. All households were visited for both the baseline and the post-intervention surveys and no sampling was undertaken. All data were collected on mobile phones in the field and transmitted to a central web based server.
In addition to questions asked in the baseline survey, to develop the post-intervention survey questionnaire we adapted validated questions related to sexual risk behaviour, HIV knowledge, and stigma from other studies in South Africa.17
Table 1 lists the predefined primary and secondary outcomes, number of items for composite indices, and the hypothesised difference between study arms.
Table 1 Primary and secondary outcome measures in home based HIV counselling and testing intervention
We carried out a sample size calculation for the primary outcome, prevalence of HIV testing. The intracluster correlation coefficient estimated from the baseline survey was 0.02. To detect an increase in the proportion of people who had an HIV test from 32% to 45% post-intervention with 90% power and significance level of 0.05, we needed eight clusters per arm (16 clusters in total) and approximately 250 participants per cluster. The conservative estimate of effect size due to the intervention was based on rates of HIV testing from national surveys at the time the study was planned.18
We summarised continuous measures by means and standard deviations, and categorical measures by proportions. We calculated prevalence ratios for all outcomes. For the main outcome and all secondary outcomes (except for the two outcomes among HIV infected people) we used a hierarchical generalised linear model for the negative binomial family taking into account the design effect by including clusters and households nested within clusters as random effects. The hierarchical model was deemed most appropriate owing to the dependency structure within households (multiple people within a household could have been tested), which needed to be taken into account. We ran this model in SAS. For the two secondary outcomes among HIV infected people we used a generalised linear model for the binomial family with a log link, taking into account the design effect through robust clustering owing to the small size of this subgroup. This model was run in Stata (version 11.0). We assessed potential confounding due to baseline differences in drinking water source, electricity, and ownership of a mobile phone. Inclusion of these factors in the model did not change the estimated prevalence ratio for the main outcome measure.
Subgroup analysis by sex was prespecified and therefore we assessed the homogeneity of the intervention effect by sex. Although we found non-significant interactions between sex and primary and secondary outcomes, for information purposes we present the main outcome stratified by sex. All statistical analyses were by intention to treat.
All participants gave oral informed consent for participation in the study, and written informed consent for HIV testing, in accordance with local district procedures. Information sheets were read and given to prospective participants in the local languages (Zulu or Xhosa) with explanations about the home based HIV counselling and testing intervention.