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Effective national and global HIV responses require a significant expansion of HIV testing and counselling (HTC) to expand access to prevention and care. Facility-based HTC, while essential, is unlikely to meet national and global targets on its own. This article systematically reviews the evidence for community-based HTC.
Methods and Findings
PubMed was searched on 4 March 2013, clinical trial registries were searched on 3 September 2012, and Embase and the World Health Organization Global Index Medicus were searched on 10 April 2012 for studies including community-based HTC (i.e., HTC outside of health facilities). Randomised controlled trials, and observational studies were eligible if they included a community-based testing approach and reported one or more of the following outcomes: uptake, proportion receiving their first HIV test, CD4 value at diagnosis, linkage to care, HIV positivity rate, HTC coverage, HIV incidence, or cost per person tested (outcomes are defined fully in the text). The following community-based HTC approaches were reviewed: (1) door-to-door testing (systematically offering HTC to homes in a catchment area), (2) mobile testing for the general population (offering HTC via a mobile HTC service), (3) index testing (offering HTC to household members of people with HIV and persons who may have been exposed to HIV), (4) mobile testing for men who have sex with men, (5) mobile testing for people who inject drugs, (6) mobile testing for female sex workers, (7) mobile testing for adolescents, (8) self-testing, (9) workplace HTC, (10) church-based HTC, and (11) school-based HTC. The Newcastle-Ottawa Quality Assessment Scale and the Cochrane Collaboration's “risk of bias” tool were used to assess the risk of bias in studies with a comparator arm included in pooled estimates.
117 studies, including 864,651 participants completing HTC, met the inclusion criteria. The percentage of people offered community-based HTC who accepted HTC was as follows: index testing, 88% of 12,052 participants; self-testing, 87% of 1,839 participants; mobile testing, 87% of 79,475 participants; door-to-door testing, 80% of 555,267 participants; workplace testing, 67% of 62,406 participants; and school-based testing, 62% of 2,593 participants. Mobile HTC uptake among key populations (men who have sex with men, people who inject drugs, female sex workers, and adolescents) ranged from 9% to 100% (among 41,110 participants across studies), with heterogeneity related to how testing was offered. Community-based approaches increased HTC uptake (relative risk [RR] 10.65, 95% confidence interval [CI] 6.27–18.08), the proportion of first-time testers (RR 1.23, 95% CI 1.06–1.42), and the proportion of participants with CD4 counts above 350 cells/µl (RR 1.42, 95% CI 1.16–1.74), and obtained a lower positivity rate (RR 0.59, 95% CI 0.37–0.96), relative to facility-based approaches. 80% (95% CI 75%–85%) of 5,832 community-based HTC participants obtained a CD4 measurement following HIV diagnosis, and 73% (95% CI 61%–85%) of 527 community-based HTC participants initiated antiretroviral therapy following a CD4 measurement indicating eligibility. The data on linking participants without HIV to prevention services were limited. In low- and middle-income countries, the cost per person tested ranged from US$2–US$126. At the population level, community-based HTC increased HTC coverage (RR 7.07, 95% CI 3.52–14.22) and reduced HIV incidence (RR 0.86, 95% CI 0.73–1.02), although the incidence reduction lacked statistical significance. No studies reported any harm arising as a result of having been tested.
Community-based HTC achieved high rates of HTC uptake, reached people with high CD4 counts, and linked people to care. It also obtained a lower HIV positivity rate relative to facility-based approaches. Further research is needed to further improve acceptability of community-based HTC for key populations. HIV programmes should offer community-based HTC linked to prevention and care, in addition to facility-based HTC, to support increased access to HIV prevention, care, and treatment.
International Prospective Register of Systematic Reviews CRD42012002554
Please see later in the article for the Editors' Summary
Three decades into the AIDS epidemic, about 34 million people (most living in resource-limited countries) are infected with HIV, the virus that causes AIDS. Every year another 2.2 million people become infected with HIV, usually through unprotected sex with an infected partner, and about 1.7 million people die. Infection with HIV, which gradually destroys the CD4 lymphocytes and other immune system cells that provide protection from life-threatening infections, is usually diagnosed by looking for antibodies to HIV in the blood or saliva. Disease progression is subsequently monitored in HIV-positive individuals by counting the CD4 cells in their blood. Initiation of antiretroviral drug therapy—a combination of drugs that keeps HIV replication in check but that does not cure the infection—is recommended when an individual's CD4 count falls below 500 cells/µl of blood or when he or she develops signs of severe or advanced disease, such as unusual infections.
Why Was This Study Done?
As part of intensified efforts to eliminate HIV/AIDS, United Nations member states recently set several HIV-related targets to be achieved by 2015, including reduced transmission of HIV and increased delivery of antiretroviral therapy. These targets can only be achieved if there is a large expansion in HIV testing and counseling (HTC) and increased access to HIV prevention and care services. The World Health Organization currently recommends that everyone attending a healthcare facility in regions where there is a generalized HIV epidemic (defined as when 1% or more of the general population is HIV-positive) should be offered HTC. However, many people rarely visit healthcare facilities, and others refuse “facility-based” HTC because they fear stigmatization and discrimination. Thus, facility-based HTC alone is unlikely to be sufficient to enable national and global HIV targets to be reached. In this systematic review and meta-analysis, the researchers evaluate the performance of community-based HTC approaches such as index testing (offering HTC to the sexual and injecting partners and household members of people with HIV), mobile testing (offering HTC through a service that visits shopping centers and other public facilities), and door-to-door testing (systematically offering HTC to homes in a catchment area). A systematic review uses predefined criteria to identify all the research on a given topic; meta-analysis combines the results of several studies.
What Did the Researchers Do and Find?
The researchers identified 117 studies (most undertaken in Africa and North America) involving 864,651 participants that evaluated community-based HTC approaches. Among these studies, the percentage of people offered community-based HTC who accepted it (HTC uptake) was 88% for index testing, 87% for self-testing, 80% for door-to-door testing, 67% for workplace testing, and 62% for school-based testing. Compared to facility-based approaches, community-based approaches increased the chances of an individual's CD4 count being above 350 cells/µl at diagnosis (an important observation because early diagnosis improves subsequent outcomes) but had a lower positivity rate, possibly because people with symptoms of HIV are more likely to visit healthcare facilities than healthy individuals. Importantly, 80% of participants in the community-based HTC studies had their CD4 count measured after HIV diagnosis, and 73% of the participants initiated antiretroviral therapy after their CD4 count fell below national eligibility criteria; both these observations suggest that community-based HTC successfully linked people to care. Finally, offering community-based HTC approaches in addition to facility-based approaches increased HTC coverage seven-fold at the population level.
What Do These Findings Mean?
These findings show that community-based HTC can achieve high HTC uptake rates and can reach HIV-positive individuals earlier, when they still have high CD4 counts. Importantly, they also suggest that the level of linkage to care of community-based HTC is similar to that of facility-based HTC. Although the lower positivity rate of community-based HTC approaches means that more people need to be tested with these approaches than with facility-based HTC to identify the same number of HIV-positive individuals, this downside of community-based HTC is likely to be offset by the earlier identification of HIV-positive individuals, which should improve life expectancy and reduce HIV transmission at the population level. Although further studies are needed to evaluate community-based HTC in other regions of the world, these findings suggest that offering community-based HTC in HIV programs in addition to facility-based testing should support the increased access to HIV prevention and care that is required for the intensification of HIV/AIDS elimination efforts.
Citation: Suthar AB, Ford N, Bachanas PJ, Wong VJ, Rajan JS, Saltzman AK, et al. (2013) Towards Universal Voluntary HIV Testing and Counselling: A Systematic Review and Meta-Analysis of Community-Based Approaches. PLoS Med 10(8): e1001496. https://doi.org/10.1371/journal.pmed.1001496
Academic Editor: Stephanie L. Sansom, Centers for Disease Control and Prevention, United States of America
Received: December 5, 2012; Accepted: June 27, 2013; Published: August 13, 2013
Copyright: © 2013 Suthar et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: The authors were personally salaried by their institutions during the period of writing. No specific funding was received for this study. No funding bodies had any role in the study design, data collection, data analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist. The opinions and statements in this article are those of the authors and do not necessarily represent the official policy, endorsement, or views of their organisations.
Abbreviations: ART, antiretroviral therapy: CI, confidence interval; FSW, female sex workers; HTC, HIV testing and counselling; MSM, men who have sex with men; PWID, people who inject drugs; RR, relative risk; WHO, World Health Organization
HIV is a leading cause of morbidity and mortality globally . Despite considerable progress in controlling the epidemic, there were approximately 2.2 million new HIV infections, 1.7 million HIV-related deaths, and 34.2 million people with HIV worldwide in 2011; 1.5 million of these new HIV infections, 1.2 million of the HIV deaths, and 23.5 million of the people living with HIV were in Africa . Given the urgency to act on the epidemic, all United Nations member states agreed to achieve the following HIV targets by 2015: (1) reduce sexual and parenteral HIV transmission by 50%, (2) eliminate vertical HIV transmission, (3) reduce tuberculosis deaths among people with HIV by 50%, and (4) deliver antiretroviral therapy (ART) to 15 million people . Achieving these targets will require people at risk of HIV to learn their status and link to prevention and care services.
In an effort to expand access to prevention and care services, World Health Organization (WHO) guidelines recommend provider-initiated HIV testing and counselling (HTC) for all people seen in all health facilities in generalised epidemics (i.e., antenatal HIV prevalence ≥1%) and in specific facilities in concentrated epidemics . While provider-initiated HTC programmes have been successful in identifying previously undiagnosed individuals in generalised epidemics, they may not reach all people at risk of HIV acquisition ,. Indeed, the latest Demographic and Health Surveys from 29 sub-Saharan African countries, representing approximately half of the global burden of HIV, indicate that only 15% of adults received results from an HIV test in the previous year . This low coverage is recognised as a critical barrier to scaling up HIV prevention and care interventions. Furthermore, people living with HIV are often diagnosed late in the course of their disease, resulting in avoidable morbidity, mortality, and transmission of the virus. .
The reasons for the current low coverage of HTC are various and include service, patient, and demographic barriers ,. For example, in generalised epidemics women have higher rates of testing than men and adolescents, perhaps because of their contact with reproductive and antenatal health services . Implementation of provider-initiated HTC guidance remains a priority for countries. However, because many people have limited contact with healthcare providers, HTC provision in health facilities alone is insufficient to achieve national and global targets. Although previous research has reviewed home-based HTC ,, the impact of all community-based HTC approaches has not been systematically reviewed. The objective of this study was to systematically review all community-based HTC approaches to inform global and national HIV programming.
Conduct of Systematic Review
This systematic review was conducted in accordance with the PRISMA statement using a pre-defined protocol (International Prospective Register of Systematic Reviews identification number: CRD42012002554; Text S1 and Protocol S1) ,. The PubMed database was searched on 4 March 2013, and Embase and WHO Global Index Medicus were systematically searched on 10 April 2012, without language, geographic, publication, date, or any other restrictions. In addition, the WHO International Clinical Trials Registry Platform, the Cochrane Central Register of Controlled Trials, the International Standard Randomised Controlled Trial Number Register, and ClinicalTrials.gov were systematically searched without language, publication, or date restrictions on 3 September 2012. Experts in the field were contacted to identify unpublished research and ongoing studies, and bibliographies of relevant studies were screened.
Community-based HTC was defined as HTC outside of health facilities. Facility-based HTC approaches were defined as those in healthcare sites (e.g., health facilities, hospitals, and fixed, stand-alone voluntary counselling and testing sites). Eleven different community-based HTC approaches were reviewed in this study: (1) door-to-door testing (systematically offering HTC to homes in a catchment area), (2) mobile testing for the general population (offering HTC via a mobile HTC service in areas visited by the general public, such as shopping centres, transport hubs, or roadside restaurants), (3) index testing (offering HTC to household members of people with HIV and persons who may have been exposed to HIV such as spouses, sexual partners, or children of people with HIV); (4) mobile testing for men who have sex with men (MSM), (5) mobile testing for people who inject drugs (PWID), (6) mobile testing for female sex workers (FSW), (7) mobile testing for adolescents, (8) self-testing, (9) workplace HTC, (10) church-based HTC, and (11) school-based HTC.
Several outcomes were analysed in this study. Uptake was calculated by dividing the number of individuals accepting HTC by the number of individuals offered HTC. The proportion of first-time testers was calculated by dividing the number of people reporting receiving their first HIV test by the total number of people tested. The proportion of participants with a CD4 count greater than 350 cells/µl was calculated among participants with HIV who had their CD4 count measured. Two steps of the retention continuum were assessed: (1) CD4 measurement (among all participants found to have HIV) and (2) initiation of ART (among participants eligible per national guidelines). In studies with a comparator arm, the HIV positivity rate was calculated by dividing the number of individuals found to be HIV positive by the number of individuals tested. HTC coverage was calculated by dividing the number of people tested by the total number of people living in the catchment area for the community-based HTC approach. HIV incidence was calculated by dividing the risk of infection in communities with access to community- and facility-based HTC by the risk of infection in communities with access to only facility-based HTC. Some of the outcomes were not independent. For example, the number of people tested was the denominator for the HIV positivity rate and first-time testers and also the numerator for HTC coverage. Moreover, the number of people living with HIV was the numerator for the HIV positivity rate and also the denominator for calculating the first step of the retention continuum (CD4 measurement). The cost per person tested was approximated by dividing the economic costs incurred during HTC in studies by the total number of people tested. Costs were adjusted for inflation from the year the costs were estimated to 2012 United States dollars using the US Bureau of Labor Statistics' inflation calculator .
Search Strategy and Selection Criteria
The search strategies (Table S1) were designed with the assistance of a librarian to identify studies including community-based HTC. Following recommendations from PRISMA, eligibility criteria were based on key study characteristics: population, intervention, comparator, outcome, and design . Specifically, studies were included when (1) the study population included people in generalised, concentrated, or low-level HIV epidemics; (2) the intervention was community-based HTC offered in combination with a background of facility-based HTC; (3) the comparator was facility-based HTC; (4) the outcome(s) included uptake, proportion of people reporting receiving their first HIV test, CD4 value at diagnosis, rates of linkage to care, HIV positivity rate, HTC coverage, HIV incidence, or cost per person tested; and (5) the study design was a randomised trial or observational cohort study. Given the lack of comparative studies for community-based HTC, studies without a comparator arm were also included if they met the remaining eligibility criteria.
A. B. S., N. F., and O. A. independently screened the abstracts of all articles identified via the literature database searches and then compared the full texts of all articles selected during screening against the inclusion criteria. Disagreements were resolved by discussion. J. S. R. and A. K. S. repeated the same process for the clinical trial registries.
A. B. S., J. S. R., and A. K. S. completed the data extraction of characteristics of study participants, community-based testing approaches, outcomes, and quality assessment using a standardised extraction form.
The Newcastle-Ottawa Quality Assessment Scale was used to assess bias in studies with a comparator arm included in pooled analyses . This scale rates studies based on eight criteria in three sources of bias. We modified this scale to remove one criterion, demonstration that the outcome of interest was not present at the start of study, since a previous HIV test may not affect all the outcomes analysed in this article. The Cochrane Collaboration's “risk of bias” tool was used to assess bias in randomised trials with a comparator arm .
Outcome proportions from studies meeting inclusion criteria were stabilised using the Freeman-Tukey-type arcsine square-root transformation and then pooled to summarise the proportion of participants who (1) accepted different community-based HTC approaches, (2) reported receiving their first HIV test, (3) had CD4 counts measured after diagnosis, (4) were diagnosed with HIV with a CD4 count above 350 cells/µl, and (5) initiated ART after their CD4 count indicated they were eligible for treatment ,. Pooled relative risks (RRs) were used to compare participants of community- and facility-based HTC with respect to uptake, proportion of first-time testers, the HIV positivity rate, proportion with CD4 counts above 350 cells/µl, and HTC coverage. Random-effects models were used for all analyses. Given the differences in HIV epidemiology, sexual mixing patterns, transmission factors, and healthcare utilisation rates for key populations, key population outcome data were reported individually and not pooled. I2 statistics were used to measure heterogeneity . I2 statistics near 25% indicate low heterogeneity, values near 50% indicate moderate heterogeneity, and those above 75% indicate high heterogeneity . All analyses were completed in STATA version 12.0.
108 articles, describing studies conducted from 1987 to 2012 and including 864,651 participants completing HTC, met the eligibility criteria (Table 1; Figure 1). Two articles were randomised trials ,, and the rest were observational in design. Data from one multi-centre cluster-randomised trial were stratified into three studies (based on the country where the testing was offered) , data from three articles were stratified based on the year community-based HTC was offered –, and data from four articles were stratified based on the community-based HTC approach used –. Given that 108 articles provided data from 108 studies and there were nine additional studies after stratification, there were a total of 117 studies included (Table S4). 76 studies were from Africa, 28 were from North America (excluding Central America), six were from Asia, four were from Central and South America, three were from Europe, and one was from Australia. The clinical trial registers identified ten ongoing trials: one on index testing , one on mobile testing , five on door-to-door testing –, one on self-testing , and two on community-based testing for key populations ,.
The percentage of participants who were male was 45.3% for index testing, 45.9% for door-to-door testing, 44.9% for mobile testing, 62.6% for self-testing, 67.0% for workplace testing, and 42.2% for school-based testing (Table 1). Excluding studies including only MSM or only FSW, 62.9% of testers were male in mobile testing for key populations (Table 1). Population-level HTC efforts found that implementation of community-based HTC increases the number of couples receiving testing (Table 2).
61 studies reported uptake of different community-based testing approaches among 713,632 participants: seven studies evaluated index testing among 12,052 participants ,,–, three evaluated self-testing among 1,839 participants –, 14 evaluated mobile HTC among 79,475 participants ,,–, 28 evaluated door-to-door testing among 555,267 participants ,,,,–, six evaluated workplace HTC among 62,406 participants ,–, and three evaluated school-based HTC among 2,593 participants – (Figure 2). The percentage of participants accepting HTC was 88.2% for index testing (95% confidence interval [CI] 80.5%–95.9%; I2 99.7%, 95% CI 99.7%–99.8%; Figure 3), 87.1% for self-testing (95% CI 85.1%–89.0%; I2 28.8%, 95% CI 0%–92.6%; Figure 4), 86.8% for mobile HTC (95% CI 85.6%–88.1%; I2 99.9%, 95% CI 99.9%–99.9%; Figure 5), 80.0% for door-to-door HTC (95% CI 76.9%–83.1%; I2 99.9%, 95% CI 99.9%–99.9%; Figure 6), 67.4% for workplace HTC (95% CI 32.8%–100.0%; I2 100%, 100.0%–100.0%; Figure 7), and 62.1% for school-based HTC (95% CI 39.6%–84.5%; I2 99.0%, 95% CI 98.5%–99.4%; Figure 8). Uptake was higher in community-based HTC compared to providing vouchers to participants for facility-based HTC (RR 10.65, 95% CI 6.27–18.08; I2 96.1%; Figure 9) ,.
Figure 9. Pooled relative risks of community-based HTC versus facility-based HTC.
The numerator for all RRs was the risk of an outcome in community-based testing, while the denominator was the risk of an outcome in facility-based testing.
19 studies reported uptake among 41,110 participants in key populations, including 16,725 MSM –, 4,681 PWID ,–, 81 FSW , 13,240 adolescents ,, and 6,383 individuals from combinations of key populations. The percentage accepting HTC was 99.7% among FSW, ranged from 13.7% to 94.5% among PWID, ranged from 9.4% to 95.0% among MSM, and ranged from 33.9% to 96.6% among adolescents (Figure 10). One study reported an uptake percentage of 95.2% among PWID and FSW , another reported an uptake percentage of 75.1% among PWID, FSW, and MSM , and another reported an uptake percentage of 60.0% among PWID and MSM . Uptake was higher for community-based testing than for facility-based testing among FSW (RR 1.10, 95% CI 1.03–1.17)  and MSM (RR 1.53, 95% CI 1.42–1.65)  (Figure 11).
Figure 11. Relative risks of community-based HTC versus facility-based HTC among key populations.
The numerator for all RRs was the risk of an outcome in community-based testing, while the denominator was the risk of an outcome in facility-based testing.
33 studies reported the HTC history among 597,016 participants in community-based HTC approaches ,,–,,,,–,–,,,,,,,,–. 62.2% (95% CI 58.0%–66.4%; I2 99.9%, 95% CI 99.9%–99.9%; Figure 12) of participants at community-based HTC sites reported receiving their first HIV test. In the nine studies with a facility-based comparator arm, a larger proportion of participants reported receiving their first HIV test at community-based HTC than at facility-based HTC (RR 1.23, 95% CI 1.06–1.42; I2 99.8%, 95% CI 99.8%–99.9%; Figure 9) ,,,,,.
17 studies reported the HTC history of 25,311 participants from key populations receiving community-based HTC ,,,,,,,,–. 9% to 79% of participants reported receiving their first HIV test (Figure 13). Five of these studies included a facility-based comparator arm (Figure 11). There were more first-time testers in community-based HTC than facility-based HTC for two study populations of MSM (RR 2.24, 95% CI 1.27–3.93  and RR 1.37, 95% CI 1.18–1.59 ); however, there were fewer first-time testers in community-based HTC for a different study population of MSM (RR 0.33, 95% CI 0.26–0.43 ). There were more first-time testers in community-based HTC than facility-based HTC for a study population including PWID and MSM (RR 1.10, 95% CI 1.08–1.13 ); however, there was no difference in the proportion of first-time testers for a study population of FSW (RR 0.97, 95% CI 0.72–1.30 ).
HIV Positivity Rate
14 studies included data on the HIV positivity rate among people testing in community-based approaches relative to people testing in facility-based approaches ,,,,,,,,–. Overall, the HIV positivity rate was lower in community-based approaches relative to facility-based approaches (RR 0.59, 95% CI 0.37–0.96; I2 99.6%, 95% CI 99.6%–99.7%; Figure 9). The median number needed to screen to identify one person with HIV in community- and facility-based HTC was 17 (range 3–86) and 6 (range 4–154), respectively (Table 3). The number needed to screen with community-based testing was highest in settings with a low national HIV prevalence: 54 in Thailand and 86 in Guatemala ,.
Six community-based testing studies for key populations included a facility-based comparator arm (Figure 11). Studies including FSW and a combination of PWID and MSM found no difference in the positivity rate for community- versus facility-based approaches (FSW, RR 0.62, 95% CI 0.29–1.34  and RR 1.39, 95% CI 0.85–2.29 ; PWID and MSM, RR 1.13, 95% CI 0.91–1.39 ). There was a lower positivity rate among a study population of MSM (RR 0.09, 95% CI 0.03–0.33 ) and among a study population including PWID, FSW, and MSM (RR 0.51, 95% CI 0.28–0.94 ). There was also a higher positivity rate among a study population of MSM (RR 2.37, 95% CI 1.35–4.15 ). The number needed to screen to identify one person with HIV varied depending on the key population and study setting (Table 4).