INTRODUCTION

It has been 30 years since the first cases of HIV infection were reported in the United States.1 The past three decades of HIV intervention research have attenuated several mechanisms of HIV acquisition. Intravenous drug use has become less relevant in the past decade,2–4 and mother-to-child prevention programs have substantively reduced mother-to-child transmission rates.5 Since the mid-1990s new HIV cases have steadily declined among whites, however, sexual transmission persists in racial minority groups fueled by sexual mixing patterns.6,7 According to a recent Centers for Disease Control and Prevention report, in 2008 the HIV diagnosis rate among blacks was 799 % higher than for whites, and 205 % higher among Latinos than whites.4 Among women the disparity is even more pronounced, with the rate of diagnosis over 1,830 % higher for blacks and 359 % for Latinas.4

Thirty years into the epidemic we find ourselves at a watershed moment, with biomedical interventions such as microbocides and pre-exposure prophylaxis (PrEP) demonstrating promise in moderating the sexual transmission of HIV.8,9 Yet there is still much we can draw from past studies in designing the future of HIV interventions. For instance, a behavioral intervention that effectively increases condom use among its participants may be adapted to promote the concomitant use of PrEP. Accordingly, as part of a symposium of systematic reviews targeting racial disparities in health care commissioned by the Robert Wood Johnson Foundation, we conducted a systematic review of interventions aimed at reducing the sexual transmission of HIV among racial minorities in the United States. Previous reviews have focused on specific population categories, international settings, intervention modalities, or specific theoretical or conceptual models, or have limited themselves to interventions tested in randomized control trials.10–14 This review builds upon previous work by including interventions targeting a range of at-risk minorities as well as those evaluated in non-randomized trials, using a standardized metric to assess the quality of each study. Further, our review differs by limiting to interventions conducted directly within or linked to a clinical setting. This criterion was standardized for all reviews in this symposium, and acknowledges the context in which forthcoming biomedical interventions will likely be implemented. Because few interventions utilized biologic endpoints such as incident HIV, we included studies that employed condom use as an outcome measure. Studies measuring only intermediate behavioral endpoints such as reduction in number of partners were not included, since improvement in these endpoints does not necessarily correlate with HIV or other sexually transmitted infection (STI) incidence.15,16 Studies that included the treatment of STIs for prevention of HIV were included. The primary objective of this review is to assemble a guide of effective interventions that reduce the sexual acquisition of HIV among racial minorities and may be implemented by health professionals in a clinical setting.

METHODS

Data Sources

The online appendix contains a description of our Electronic Databases Search, Manual Searches, Data Synthesis and Quality and Bias Assessment. The final search was completed on the 30th anniversary of the first reported case of HIV infection, so that articles published before June 5, 2011 were eligible for inclusion.1 Databases searched included MEDLINE search engine, the Cochrane Review of Clinical Trials, CINAHL, and PsycINFO. A bibliographic review of previous reviews was also conducted to further identify interventions.

Study Selection

The operational definition of intervention used during our search was an explicitly stated intervention designed to decrease the sexual acquisition of HIV within a racial or ethnic minority population in the United States.17 Inclusion criteria included the following:

  1. 1)

    Population composed of at least 50 % minority adults or adolescents of any ethnic or cultural background, or race/ethnicity sub-analyses.

  2. 2)

    Formal health care association, either through participant recruitment (e.g. sexually transmitted infection clinics, health center outpatients) or location of intervention implementation (e.g. community health center, clinic waiting room).

  3. 3)

    Conducted in the United States

  4. 4)

    Condom use or biological endpoint

  5. 5)

    Publication as a full manuscript or brief report in English

We excluded “prevention for positives” interventions, because these interventions to prevent the onward transmission of HIV by seropositive patients differ greatly from those to aiming to prevent HIV acquisition by seronegative patients. Studies that focused primarily on curtailing substance use in people at risk for HIV were also excluded; though changing substance use patterns may affect rates of risky sexual behaviors, it was felt that an evaluation of substance use interventions in minority populations was outside the scope of the current review. We did not limit inclusion by study design and no time frame criterion was used.

All included manuscript citations were compiled into a single “library” using citation manager software (EndNote X3, 2009). A single research assistant conducted a first pass through the articles, sorting manuscripts as “include”, “exclude” or “uncertain” based on title and abstract. A second pass was conducted by the study authors. Articles marked “uncertain” from both passes were reviewed a third time by the lead and final authors to determine eligibility (Fig. 1). Included manuscripts were then sorted based on target population as described by authors of the reviewed studies. These target population categories were STD clinic patients, adolescents, drug users, “high-risk” women or men (i.e., those reporting frequent unprotected sex, concurrent partners, or men who have sex with men), “vulnerable” women (i.e., low-income women), and “other”. Within target population, interventions were stratified by delivery method (peer delivery, health worker delivery, or digital delivery).

Figure 1.
figure 1

Criteria used for analysing HIV-prevention interventions targeting racial minority population.

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Quality Assessment

To assess study quality, each study was rated using a scoring algorithm specifically developed for this symposium18 modified from that proposed by Downs and Black.19 The original Downs and Black score is calculated by rating each study across a variety of domains including reporting (nine items), external validity (three items), bias (seven items), confounding (six items), and power (one item). We simplified scoring of the power item from a five-point range to a binary system, granting one point (1) for adequate power calculations or no points (0) if power was not adequately addressed. We added one item from the Cochrane tool20 for bias assessment that was not captured by the DB protocol, for a maximum modified DB score of 29. The average DB score of 213 studies included in the first set of systematic reviews commissioned by the Robert Wood Johnson foundation was 17.65 out of a maximum of 27 point (the scoring instrument used in these reviews excluded the power item and Cochrane-derived bias item).21 Initial ratings for this review were conducted by the first four authors and two trained research assistants, using a Microsoft Access database designed for this symposium to calculate the DB score for each study. As a quality control measure, 20 % of studies were re-scored by the final author, and the inter-rater agreement for quality score using the modified DB tool was adequate (κ = 0.67).

The database simultaneously captured further information about the journal of publication, study design, follow-up time, subject demographics, and outcomes. Linear regression was used to examine trends in DB score over time. All analysis was performed using STATA software version 11.0.

RESULTS

Study Design and Quality

No study was identified that sought specifically to reduce racial disparities in the sexual acquisition of HIV. A total of 76 articles published between 1981 and 2011 that describe interventions to prevent the sexual acquisition of HIV in minority populations were identified, and are listed according to target population in Tables 1, 2, 3, 4, 5, 6 and 7. Nearly 87 % (66) of the studies were randomized controlled trials; the remainder included 7 (9 %) pre- and post- observational studies, and a mixture of other observational studies (3; 4 %). According to our modified DB scoring system, the quality of the 76 intervention studies ranged from 15 to 29 with a mean of 22.44. Following a previously published DB rating system,19 sixty-three (83 %) of the studies were rated as very good (>20), 12 (16 %) as good (16–19), and only 1 (1 %) as fair (11–15); no study was rated poor (≤10). In linear regression analysis, a borderline significant linear trend of increasing quality over time was observed (r = 0.11; p = 0.075).

Table 1 HIV Prevention Interventions Targeting Adolescents (n = 15)
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Table 2 HIV Prevention Interventions Targeting Drug Users (n = 13)
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Table 3 HIV Prevention Interventions Targeting STD Clinic Patients (n = 16)
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Table 4 HIV Prevention Interventions Targeting High-risk Men (n = 2)
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Table 5 HIV Prevention Interventions Targeting High-risk Women (n = 5)
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Table 6 HIV Prevention Interventions Targeting Vulnerable Women (n = 15)
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Table 7 HIV Prevention Interventions Targeting Other Populations (n = 10)
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Populations and Settings

The majority of studies 61 (80 %) included over 50 % African American participants, with 22 (29 %) of these study groups composed exclusively of African Americas. Eleven studies (14 %) included a majority of Latino/a participants, with 6 (8 %) exclusively Latino/a studies. The remaining 4 (5 %) interventions included some combination of African American, Latino/a, Asian, or other non-white participants resulting in an overall ≥50 % racial minority population. Interventions were located in every region of the United States22 with 23 (30 %) studies taking place in the South, 17 (22 %) in the Northeast, 14 (18 %) on the West coast, 13 (17 %) in the Midwest, 8 (10 %) across multiple regions, and 1 intervention that did not specify location.

The most common target population was STD clinic patients, with 16 (21 %) interventions among this group. Fifteen (20 %) studies targeted adolescents, 15 (20 %) vulnerable women, 13 (17 %) drug users, 5 (6 %) high-risk women, 2 (3 %) high-risk men, and 10 studies (13 %) targeted other groups.

Intervention Delivery Method

Health worker delivery was the most common delivery method (65 %), followed by digital delivery (21 %) and peer delivery (14 %), although it is important to note that all digital and peer interventions were delivered with some health worker facilitation. Thirty-eight (50 %) interventions included condom use skills training, while the remaining half relied on didactic or interactive content, or a combination of these two. Finally, 22 (29 %) studies consisted of a single intervention session, while the majority (51; 67 %) included multiple sessions, and two studies compared single versus multiple session interventions. Two (3 %) interventions did not involve sessions, and instead employed social marketing23 or social network-based strategies24 to disseminate prevention messages.

Outcome Measures

Each intervention evaluated condom use as an outcome as a result of our inclusion criteria; nineteen (25 %) studies additionally measured incident STIs, including 6 (9 %) that specifically sought incident HIV (though sero-incidence was generally too low to draw meaningful conclusions). For the 6 studies with HIV sero-incidence as an outcome, the overall rate of new infection was 0.1 % (95 % CI [0.0 %, 0.4 %]) in the intervention groups.

Target Populations

Tables 1, 2, 3, 4, 5, 6 and 7 summarize the results for each target populations as defined by the study authors. Salient findings from studies that target populations currently at greatest risk for HIV in the United States are reviewed in detail below.

Adolescents

A number of interventions for adolescents have been developed and tested in recent years. An important feature of successful interventions targeting this demographic of individuals who are near the age of sexual debut is the presence of skills-based instruction on both appropriate condom use and effective ways of negotiating condom use with a partner. As early as 1992, Jemmott and others describe an intervention for African American male adolescents that led to a decrease in number of sexual partners and increased condom use after 3 months of follow-up, compared to a control group. The intervention was specifically designed for this population, and served to both educate adolescents about HIV/AIDS and teach condom usage and safe-sex negotiation.25 In another intervention trial for adolescents, skills-based training resulted in a greater proportion of initially abstinent adolescents who remained abstinent after one year of follow-up, compared with an information-only intervention that lacked skills-based instruction.26

An intervention that includes these essential elements and is successfully tested in an adolescent population may be adapted for a variety of aims, as long as the core elements of skill-based content and appropriate cultural targeting remain. For example, a landmark multi-session intervention for sexually active African American adolescents was developed which led not only to an increase in the proportion of adolescents reporting consistent condom use and a decrease in the proportion of adolescents reporting a recent new sexual partner at 1-year follow-up, but also to a decrease in the proportion of adolescents with chlamydial infection after 1 year, when compared to controls.27 This intervention was implemented by both African American health professionals and peer educators, and involved discussions about African American womanhood in addition to condom use and social skills instruction. Using the same core framework, this intervention was successfully expanded to include STI treatment vouchers for male sexual partners, telephone reminders to reinforce safe sex behaviors in female African American adolescents,28 and offered to pregnant African American adolescents attending prenatal clinics.29

Several studies examined the unique effects of interventions among Latino adolescents, and while the importance of skills training in this subpopulation has been confirmed, the importance of culturally-specific instruction appears to vary. Among participants with overall low rates of sexual activity, an intervention targeting Latino adolescent children and their parents that included material related to mediating the divide between Hispanic and American culture in addition to HIV-specific prevention material led to a significantly lower proportion of adolescents reporting unsafe sex at last intercourse when compared with control interventions which did not include culturally specific material.30 Additionally, a couples-based intervention drawing on culturally specific values and featuring skills-based training reduced the proportion of unprotected sex acts for Latino adolescent mothers and their sexual partners at 6 months of follow-up, compared to control group couples who received didactic messaging devoid of skills training or a cultural component.31 However, a skills-based intervention implemented by African American educators in a mixed cohort with both African American and Latino adolescents was more successful than the didactic control, with no significant difference in impact on STI rates or sexual risk behavior between the two racial groups.32

Several studies have attempted to adopt the above insights using digital or other media to develop economical interventions for adolescents with mixed results. One intervention for primarily African American young adolescents was implemented in the offices of private practice pediatricians. While waiting to see the physician, adolescents listened to an audiotape that encouraged discussion about safe sex with their pediatricians. Condom use rates improved at 3 months, though no significant effect was observed after 9 months of follow-up.33 A culturally appropriate video intervention for African American adolescent males in STD clinics demonstrated no improvement in the proportion of adolescents reporting consistent condom use, compared with individual counseling from a health educator or routine STD clinic care.34 However, a 30-minute interactive video intervention for sexually active adolescent females recruited from several health care settings, when compared to control paper-based educational materials, was associated with an increase in condom use and a 50 % decrease in the proportion of adolescents reporting chlamydia diagnosis after 6 months.35

STD Clinic Patients

We identified 16 studies examining interventions targeting patients seeking care in STD clinics. STD clinics serve a high-risk population that, by virtue of having acquired an STI, has demonstrably been failed by previous interventions. As with adolescents, many successful interventions integrate condom use instruction and negotiation skills with culturally specific motivation to employ safe sex practices. For women, a multi-session intervention that incorporated education regarding STIs, the mechanics of condom use, and condom negotiation skills resulted in a decrease in STI acquisition in African American and Latina women at 12 months of follow-up, compared with routine STI care. Of note, the implementation was culturally tailored to the target population and facilitators were matched by ethnicity to participants, however racial subgroup analyses were not performed.36

Unlike adolescent-targeted programs, successful interventions among STI clinic patients may leave out condom application instruction and focus solely on the skills of negotiating condom use. Presumably this is because STD clinic populations are older, and neglect to use condoms on account of various social and cultural implications rather than a lacking skill set. In a landmark multicenter prospective trial published in 1998, subjects exposed to both a four-session theory-based intervention and a brief two-session interactive counseling intervention demonstrated a 20 % lower risk of subsequent STI acquisition than subjects who received standard STI care at 12 months of follow-up, but only those who received the four-session intervention reported an increase in condom use compared with the control group at six months.37 Neither intervention included instruction on the mechanics of condom use, but focused instead on motivating condom use and negotiating safe sex. The subjects in this trial were African American (59 %) and Latino (19 %), though no racial subgroup analysis was conducted and race-specific content was not included.37,38

As with adolescents, interventions that employ the above insights with video or digital implementation have been developed in recent years. Video interventions, although limited due to a lack in interactivity, do offer the benefit of ease of implementation.39–41 Computer technology may overcome some of the limits of video interventions due to its interactive nature; one computerized intervention for STI clinic patients was designed to customized the material provided based on a patient’s baseline sexual risk and willingness to change behavior. This program resulted in an increased proportion of subjects reporting consistent condom use at 6 months and decreased proportion with recurrent STIs.42

High-risk Men

African American men who have sex with men (MSM) have had disproportionately high rates of HIV infection for some time43, yet we only identified a single intervention targeting this at-risk population. Of note, this intervention was not evaluated in a randomized control trial. This four-session intervention resulted in a significant decrease in the proportion of men reporting unprotected anal intercourse after three months of follow-up, as well as a decrease in the number of male and female partners with whom the respondents reported engaging in unprotected intercourse.44 This study was significantly limited by its small size, the substantial proportion of men who were lost to follow-up, and the lack of a control intervention. A second intervention targeting Latino migrant MSM was identified, and involved training community representatives to be promotores (promoters) of safe sex behaviors. Serial surveys of community members over two years demonstrated an increase in the proportion of protected anal intercourse.24 However, other interventions were simultaneously implemented in the community and the observed increase in protected sexual intercourse cannot be attributed to this intervention alone.

High-risk Women

We identified five studies evaluating interventions which primarily targeted high-risk women. Similar to the results observed in other populations, these studies suggest that cultural targeting and explicit skills instruction play an important role in determining intervention success. The relative importance of cultural targeting and skills-building, however, may depend on the specific sub-population of high-risk women targeted.45,46 For example, Raj et al. found that an HIV-intensive intervention targeting Latinas that featured condom negotiation exercises and further empowerment-based teaching, as well as a culturally tailored general woman’s health intervention featuring condom-negotiating exercises were able to improve condom use rates.47

DISCUSSION

We identified a large number of relevant studies, targeting different behaviors and conditions that place populations at risk for HIV. Given the heterogeneity of study designs and populations, sweeping conclusions are difficult. However, several salient points are worth noting. First, there were no studies specifically aimed to reduce disparities in HIV acquisition or risk behavior between racial/ethnic categories. This may be due to changes in the populations most affected by HIV, or perhaps targeting racial/ethnic minorities implies a reduction in disparities. Second, few interventions utilized HIV incidence as a primary endpoint, and those that did had negative findings. Third, very few of the identified interventions targeted men who have sex with men, the group currently at highest risk for HIV in United States. Finally, for interventions measuring behavior change, educational interventions alone did not cause meaningful change; rather, successful interventions incorporate the teaching of specific skills necessary to initiate and maintain behavioral change, and interactive interventions are superior to interventions which depend on the passive acquisition of knowledge.

Although interventions need not be specifically designed for one racial or ethnic minority, the use of peers or lay health workers of the minority population of interest allows for nuanced customization of the intervention design and leads to increased acceptance of suggested behavioral changes among target populations. Peer or lay health worker-based interventions linked to a clinical setting appeared to have better outcomes among adolescents than other study groups. Interventions varied across population categories as to whether the matched interventionists were at the level of health care staff, facilitators, or peer educators. Interestingly, only one study explicitly compared the importance of racial matching in a video intervention48, and no study specifically compared racially matched compared with unmatched implementers for interventions delivered in person.

Two previous meta-analyses comparing the results of interventions with four or more sessions to those requiring fewer sessions have concluded that interventions with four or more sessions were more effective than interventions with fewer sessions.13,14 However, none of the studies included in these prior reviews directly manipulated the number of sessions as part of the trial. We identified two studies that directly examined number of sessions; one found no difference in intervention effects across groups assigned to two versus four sessions,37 and the other found that patients randomized to an eight-session intervention had significantly better outcomes than zero-session controls, while those assigned a four-session intervention did not.49 Darbes’s meta-analysis of African American heterosexuals found that interventions were more effective if they were skill-based, peer-based, and culturally tailored for African Americans.12 Herbst’s meta-analysis of 20 interventions among Latinos found significantly greater efficacy associated with interventions that included problem-solving skills coaching, that did not use peers, and that addressed the influences of machismo.13 We extend the results of previous reviews by including a number of articles published in the last few years; the 2007 review by Crepaz et al. only includes articles published through June 2005,10 while our review includes 18 articles published since, including six interventions targeting adolescents, four targeting STD clinic patients, and the only two interventions identified in our review targeting high-risk men. Also, 10 of the studies in our review describe interventions not tested in randomized control trials. The majority of these non-randomized studies followed a pre- and post-intervention observational design. Of note, this included both of the interventions targeting high-risk men and four studies targeting vulnerable women.

Our conflicting results regarding the benefits of peer-based versus health worker-based interventions may result from confounding by ethnicity. A previous meta-analysis designed to examine this very topic across various populations (including internationally) found that health-worker-based interventions were more efficacious, but that effective interventions were more likely to match health-worker ethnicity with that of the target audience.50

We did not identify any study that specifically listed implementation costs or that performed a cost-effectiveness analysis. We highlighted above the interventions which require minimal personnel time or training, but this is at best a proxy for the true cost of an intervention. Future intervention evaluations should attempt to estimate the expected cost of implementation in order to facilitate cost-effectiveness comparisons between HIV prevention interventions for community providers, a point which has been made by authors of previous meta-analyses in this field.13 In an era of shrinking public health budgets,51 digital interventions can be expected to be a growing area of interest as a method of inexpensively promoting HIV prevention.

In the international setting, biologic interventions such as circumcision and pre-exposure prophylaxis with systemic or topical antiretrovirals have been evaluated. We did not find any published studies implementing such interventions in minorities in the United States. The 2010 iPrEx pre-exposure prophylaxis study included two U.S. sites, but since these sites accounted for less than 10 % of the total study cohort and site-specific analysis was omitted, this study did not fit our inclusion criteria.8 Finally, we note a significant lack of interventions targeting high-risk men, MSM in particular. Many of the studies that targeted STD clinic populations may have included some MSM, however, study participants were not stratified by sexual preference, and no part of the interventions specifically targeted MSM. This may be due to a number of reasons including accessibility of these men, and perhaps a long-standing focus on white MSM.

Our review features a number of limitations, foremost being those of scope. This review focused on clinic-based interventions and may have excluded a number of effective interventions that were implemented entirely in community settings. Furthermore, possibly effective interventions that were only assessed via intermediate outcomes such as intention to use condoms were not included. However, interventions that utilize proximate measures often do not correlate with biomedical outcome measurements such as incident STIs or HIV infection.15,52 Publication bias of mostly effective studies may have excluded other studies that used HIV incidence as an outcome from our review. Also, we only included studies targeting drug users which sought to reduce sexual acquisition of HIV, excluding such interventions as the provision of sterile hypodermic syringes, because we could not disentangle the mechanism of transmission in this population and had to rely on reported condom use. Potential biases due to study duration were not assessed and our analysis was not powered to detect a statistical difference between study quality and publication date. Comparing our review to other reviews is limited by the use of a unique modification of the DB scoring system used in this symposium which was chosen to allow the evaluation of both randomized and non-randomized studies.53 However, the original DB system has been used extensively by reviews in other health settings, with the original paper having been cited over 800 times since publication. It is worth emphasizing that the DB scoring metric evaluates the quality of the study evaluating an intervention, not the intervention itself. Our modification to the DB system to de-emphasize the importance of power calculations does complicate direct comparisons with previous uses of the scoring metric, but was done because many studies omit results of power studies in their texts.54

In summary, interventions which incorporate the teaching of specific skills necessary to initiate and maintain behavioral change, and interactive interventions are superior to interventions which depend on the passive acquisition of knowledge. Peer-based interventions seemed to be more effective in adolescents compared to other groups. Serious lacunae in interventions that target minority MSM and a total lack of interventions designed to reduce disparities was evident. Future work should seek to fill these gaps as well as adapt current interventions effective in minority populations to include forthcoming biomedical HIV/AIDS interventions where appropriate.