Introduction

Adolescent boys experience increased HIV prevalence as they age, and adolescence may be a critical time for the formation of attitudes toward sex and sexual behaviors [1]. In sub-Saharan Africa (SAA), the epicenter of the HIV epidemic, 43% of boys and 53% of girls have had sex before age 18 in the period between years 2000 and 2015 [2]. Despite adolescent boys and men (ABYM) being at lower risk of HIV acquisition than girls, they are still at risk due to a combination of high frequency of sexual behaviors including condomless sex, sex under the influence of alcohol, and multiple sexual partnerships as well as poor health-seeking behaviors, such as not getting treatment for sexually transmitted infections (STI) and not testing for HIV [3]. There were 46% fewer deaths due to AIDS-related illness among girls and women in 2019 than in 2010, compared to 32% fewer deaths among ABYM over the same period, indicating a worse AIDS mortality risk for ABYM than for AGYW [4]. Indeed, adolescents experience complex physical, psychological, and social changes during the transition from childhood to adulthood. They encounter legal constraints (e.g., legal age of consent to HIV testing and counseling ranges between 12 and 18 years in SSA), cultural inhibitions against sexuality education, and material poverty-inducing exploitative sexual relationships. These factors restrict adolescents’ access to HIV services at a time when they are becoming sexually aware and lack knowledge and skills, thus enhancing their risk of HIV and other STI. The vulnerability to HIV and mortality among ABYM in SSA is exacerbated by their low social and economic position, as Gafos points out [5]. Their developmental, social and economic challenges highlight the urgent need to document and assess sexual risk-reduction interventions in the published literature targeting ABYM aged 10–24 years.

ABYM are seldom addressed in HIV prevention policies and programs. Several reviews have assessed the impact of HIV on adolescents in general, but few have focused on ABYM [6, 7]. Much of the available data do not disaggregate adolescent boys from adult males or adolescents in general; yet the contexts and life challenges of ABYM can be markedly different from those of other ages or genders [8,9,10]. Therefore, a scoping review is warranted to assess interventions targeting ABYM in SSA. Scoping reviews are a “preliminary assessment of potential size and scope of available research literature” [11, p. 95]. They aim to identify the nature and extent of research evidence and identify gaps in the literature so as to inform policy and practice.

This review complements other published reviews of sexual risk behaviors among adolescents and young people in SSA [12, 13] but differs from previous reviews in three major ways. First, the current review focuses on interventions that either target ABYM exclusively or includes the ABYM population and disaggregates results by age and gender. This is appropriate given the high emphasis placed on AGYW-focused HIV prevention interventions (e.g., DREAMS interventions being implemented in 10 SSA countries) [14] and that previous studies have combined ABYM data with AGYW or older male data [9, 15]. Second, the scope of the review is extended to include biomedical, behavioral and structural interventions that mitigate HIV risk for ABYM since previous reviews have tended to focus on psychosocial behavior change interventions only, for example [12]. Third, unlike previous reviews which have focused on either out-of-school or in-school interventions, the current review includes both in- and out-of-school data. Findings based on this review have implications for amplifying and fine-tuning the delivery of differentiated HIV prevention strategies for ABYM.

More specifically, the aim of this review is to provide an overview of interventions that have targeted sexual risk behaviors of ABYM in SSA between 2000 and 2020, with critical insights on ‘what works’ in preventing risky sexual behavior that could lead to HIV transmission. The central research questions of the review are as follows: What evidence-based HIV-directed sexual risk-reduction interventions exist for ABYM in SSA over the review period in the published or grey literature, and how effective have these interventions been in mitigating HIV risk?

Methods

The methodological framework proposed by Arksey and O’Malley was adopted to guide the scoping review [16]. This framework emphasizes (a) identifying the research question, (b) identifying relevant studies, (c) selecting eligible studies, (d) charting of data, and (e) collating, summarizing and reporting the results, and supports the comprehensive ‘mapping’ of relevant literature in the field of interest. The study used the population, concept and context framework recommended by the Joanna Briggs Institute for Scoping Reviews [17].

Inclusion Criteria

Characteristics of Study Population

In this review, we only considered ABYM between the ages of 10 and 24 years. We focused solely on ABYM in response to the lesser focus on HIV interventions targeting ABYM [7]. Since 2015, HIV interventions in SSA have mainly centered on AGYW. In this review, studies included sub-populations within a broad age range: males in early (10–14 years), middle (15–17 years) and late adolescence to young adulthood (18–24 years). We included studies that comprised AGYW only if results were disaggregated by gender and age.

Studies of Interest

We included studies evaluating HIV behavioral, biomedical, social and structural sexual risk-reduction interventions, detailing their effectiveness in reducing sexual risk among ABYM 10–24 years. The comparators could be different interventions or strategies: (a) inter- and intra-men groups; (b) within or between interventions (behavioral, biomedical, or structural); or (c) across gender, such as outcomes for ABYM vs. AGYW.

Context

The context of this review encompasses both location and time dimensions. Studies from SSA (i.e., a constituent of the World Health Organization Africa region most severely affected by HIV) between 2000 and 2020 were considered for the review.

Types of Studies

In this review, we included peer-reviewed and published data that were based on qualitative, quantitative and mixed methods research. Experimental- and quasi-experimental studies, randomized controlled trials, evaluation surveys, controlled before and after studies, and impact evaluations were included. Only English-language studies were considered due to a lack of resources to analyze studies published in other languages.

Search Strategy

To execute the search for relevant studies, we followed three main steps recommended by the Joanna Briggs Institute [17]. The first step was a preliminary search of relevant databases, namely Cochrane Database of Systematic Reviews, Google Scholar, Joanna Briggs Library, MEDLINE/PubMed, Scopus, International Initiative for Impact Evaluation (3ie), and Web of Science. This was followed by an analysis of text words contained in the title and abstract, and of the index terms used to describe the article. We then conducted a second search using all identified keywords and index terms across all included databases. Finally, the reference lists of all identified reports and articles were searched for additional studies.

Study Selection

The protocol and review team comprised two screeners and two reviewers. The first level of screening targeted only the title and abstract of citations. Both screeners conducted a comprehensive title screening by searching and uploading all literature search results on Endnote 20 software. These were reviewed by both reviewers; conflicts, duplications, and discrepancies were resolved. The literature was grouped into categories (Category 1—Relevant, Category 2—Not relevant, and Category 3—Potentially relevant). Abstracts were grouped under Category 3 if age and gender were not specified. The full-text articles of studies that satisfied the inclusion criteria (Category 1) were obtained. A final decision on inclusion was made by both reviewers and any uncertainties were resolved. All citations deemed relevant after the title and abstract screening were obtained for subsequent review of the full-text article. For articles that were not fully available electronically (abstracts only), the corresponding authors or journals were contacted for assistance in procuring the article. All articles deleted from the Endnote library were saved in a separate folder to ensure the reproducibility of the study. Table 1 presents the search string used to identify relevant studies.

Table 1 Keywords and search strategy
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Results

The search strategy identified 8500 records through database searching. Duplicates were removed and 1312 citations were imported for screening. An additional 25 records were identified through other sources. These citations were screened according to the title and 105 duplicates were removed. The resultant 1232 were further screened based on abstract relevance, with 1090 records being excluded. The remaining 142 abstracts were retrieved as full records and further subjected to screening according to the inclusion criteria; 113 records were excluded, yielding 29 records for inclusion in the review. Figure 1 presents a flow chart of search and study selection results.

Fig. 1
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Flow chart for result of search and study selection

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Quality Assessment of Eligible Studies

The study quality was assessed independently by two reviewers (RK and AD) using the methodological quality criteria Mixed Methods Appraisal Tool (MMAT) as outlined in Souto et al. [18] and Hong et al. [19]. Table 2 shows the assessment of the 29 studies included in the review. Overall, the quality of included studies was excellent, with 18 of 29 studies scoring 80–100%, six studies scoring 60% (i.e., fair to intermediate), and the last five being of poor quality, scoring 40%. Similarly, risk of bias was assessed across several domains as presented in Table 3, indicating studies have low to intermediate concerns overall.

Table 2 MMAT study quality assessment
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Table 3 Risk of bias domains
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Data Collection

We manually extracted the data on intervention design, sample size, length of follow-up, and sexual-risk related outcomes for all 29 studies using data retrieval rubrics from the Joanna Briggs Institute of Meta-Analysis of Statistics Assessment and Review Instrument Quantitative (JBI-MAStARI) for quantitative studies [49] and Briggs Institute Qualitative Assessment and Review Instrument (JBI-QARI) for qualitative studies [50, 51].

Findings

In total, 29 studies were eligible for inclusion in this review. An overview of the sexual risk behavior interventions targeting ABYM in SSA and specific details about populations, study designs and key outcomes related to the study aim and research questions are displayed in Tables 4, 5, and 6.

Table 4 Description of the interventions in the scoping review
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Table 5 Intervention outcomes (descriptive)
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Table 6 Intervention outcomes (Statistical results)
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Description of Studies

Specific details of the 29 eligible studies are discussed in the summary below.

All interventions were from ten SSA countries i.e., South Africa [20,21,22,23,24,25,26, 34, 37, 39, 42, 43], Uganda [27, 30, 33, 41], Zimbabwe [38, 40, 48], Zambia [28, 36], Kenya [31], Tanzania [35, 47], Ethiopia [29], Nigeria [45], Eswatini [46] and Malawi [32]. One study was conducted in two countries [44], i.e., South Africa and Zambia. Of the 29 studies, 13 were randomized trials [22, 24, 34,35,36,37,38,39,40,41,42, 46, 48], six were quasi-experimental trials [28,29,30, 32, 43, 45], two were surveys [33, 47] and the remaining were either intervention evaluation studies or non-experimental studies, i.e., qualitative studies.

Characteristics of Study Design

Theories and models help us to better understand the logic of an intervention. Eleven studies were guided by at least one theory to explain causal pathways of HIV risk, namely, social learning theory [20, 32, 38, 40], theory of positive normativity [20], social identity theory [21], theory of gender and power [29], theory of reasoned action [32], ecological systems theory [34], social cognitive theory [42], and theory of self-efficacy [46]. Models were also cited to explain or predict behaviors. Sixteen intervention studies utilized models to inform the intervention i.e., social ecology model [20], biomedical model of health [23, 27, 44], participatory learning model [24], human rights framework approach [25], Ubuntu model [26], health belief model [30], transtheoretical model [36], sustainable livelihoods model [39], gender-transformative approach [33, 41, 43] and the Sahwira (friendship) model [48]. Models simplify a theory or concept for a better understanding of the intervention. A combination of both theory and model was used in two studies [20, 46] to enhance their findings.

Intervention approaches were varied, with the majority of interventions using a combination-type approach. UNAIDS specifically defines combination HIV prevention as rights, evidence, and community-based programs that promote a combination of biomedical, behavioral, and structural interventions designed to meet the HIV prevention needs of specific people and communities [52]. The goal is to reduce the number of new HIV infections through coordinated activities with a greater sustained impact [53]. Messages include biomedical, norm-changing, behavioral, structural and psychosocial determinants of HIV transmission and vulnerability, all of which are strong predictors of health outcomes.

Intervention delivery was through mass media in seven intervention studies [20, 21, 29, 30, 33, 42, 47], community dialogue in 14 studies [20,21,22,23,24,25,26, 30, 33, 36, 39, 41, 42, 44], drama skits, poetry, puppetry and role play in ten studies [22, 27,28,29, 33, 35, 40, 42, 45, 46]. Eighteen studies were delivered through workshops and educational curricula [20, 22, 24,25,26,27,28,29,30, 32,33,34,35,36, 39, 40, 42, 46], and seven studies were delivered through interactive games [21, 22, 33, 37, 38, 40, 42].

Half of the interventions targeted a male population exclusively [20,21,22,23, 25,26,27, 29, 33, 36,37,38, 40, 42, 48], with two of these specifying heterosexual behaviors as their inclusion criteria [25, 33]. The remaining half targeted a mixed-gender audience, as specified in our study inclusion criteria. Eight interventions worked with trained facilitators [24, 26, 29, 30, 32, 35, 44, 47] and seven with peer counselors [25, 28, 33, 34, 39, 43, 48]. Two interventions had trained peer facilitators [28, 43]. Four interventions worked with trained medical personnel [23, 24, 27, 46], four with well-known soccer ambassadors to positively influence their population [20, 21, 38, 40], four with facilitators with desired characteristics such as religious leaders in The One Man Can Campaign [22], same-sex facilitators in the Stepping Stones intervention [24], facilitators who were not regular patrons of shebeens or drug addicts in the Champions League intervention [37], and recently circumcised coaches in Make the Cut + [38].

Interventions included both in- and out-of-school audiences. Twenty interventions [20,21,22,23,24,25,26,27, 29, 30, 32, 33, 36, 37, 39, 41, 42, 44, 47, 48] targeted out-of-school youth, and nine interventions targeted in-school youth [28, 31, 34, 35, 38, 40, 43, 45, 46]. Interventions were implemented in different contexts. Thirteen interventions were in urban areas [25, 28, 33,34,35,36,37, 39,40,41, 44, 45, 48], five in peri-urban areas [27, 29, 30, 38, 43], four in rural areas [22, 24, 26, 32], and five combined either urban, rural or peri-urban areas [20, 21, 23, 31, 47]. Two interventions did not specify their geographic areas [42, 46].

Overall, the exposure to the interventions varied with follow-up assessments ranging from as short as 2 weeks post-intervention in the Zambian Peer intervention study [28] to 5 years in the African Youth Alliance intervention study [30].

Measured Outcomes

Reviewed studies investigated behavioral, norm-changing, biomedical and structural outcomes, reporting both positive and negative outcomes as well as no effect outcomes.

Behavioral Outcomes

Twenty-four intervention studies had measures relating to behavioral outcomes [20,21,22, 24,25,26,27,28, 30,31,32,33,34,35,36,37, 39,40,41,42,43, 45, 47, 48].

Condom Use

Of the interventions with a behavioral component, 15 studies measured outcomes related to condom use [22, 24,25,26,27,28, 30, 31, 34,35,36, 41, 42, 45, 48], with ten of these employing a randomized design [22, 24, 26, 34,35,36, 41, 42, 45, 48]. All findings were self-reported through questionnaires or surveys. A general improvement in condom use was reported in eight intervention studies [22, 24, 26, 27, 36, 41, 42, 45], with condom use being consistent in the Condom Technical Skill intervention study at 12-month follow-up [27]. Of the 15 study interventions, seven focused exclusively on males [22, 25,26,27, 36, 42, 48], and the remainder targeted a mixed-gender population. Condom use interventions had differential impacts by gender: condom use was higher in boys aged 12–14 years when compared to girls in the same age range in three mixed-gender intervention studies. For example, in the PATH-Kenyan Scouts intervention, the proportion of sexually active boys aged 15–18 years using condoms increased compared to girls of the same age [31]. Likewise, in the Africa Youth Alliance (AYA) intervention, condom use was higher in males than females at 5-year follow-up [30] as well as in the PREPARE intervention where condom use was higher in males and intention to use condoms was higher in females, at 6 and 12-month follow-up periods [35]. The impact was different depending on gender and school grade in the Healthwise intervention, a curriculum-based randomized trial for boys and girls (mean age 14) conducted in four urban secondary schools in South Africa [34]. Eighth grade lessons had a positive impact on girls, who responded better to the sexual risk and condom use self-efficacy lesson, compared to boys, whereas ninth-grade lessons had a positive impact on boys who self-reported higher condom use self-efficacy compared to girls at the 12-month follow-up. Improvements in intention to use condoms were recorded in the Zambian Peer Sexual Intervention study but this effect was not sustained during the 6 months that followed the intervention [28]. The Sahwira intervention reported no difference in self-reported condom use at 6-month follow-up when comparing pre- and post-intervention reports in both control and intervention conditions [48]. The intervention, a randomized controlled trial, targeted men 16 years and above and used the concept of ‘drinking partners’ to influence each other to avoid high-risk sexual encounters fueled by drinking at a beerhall.

Multiple Sex Partners

Multiple partner sex was measured in nine intervention studies [20, 22, 24, 27, 28, 41, 42, 45, 48], with five of these studies using a randomized design [22, 24, 41, 42, 48]. A self-reported decline in multiple sexual partnerships was reported in six studies at 12-month follow-up [20, 22, 24, 28, 41, 45]. Three interventions [27, 42, 48] did not have a significant effect on multiple sexual partnerships, with the Condom Technical Skills intervention reporting an increase in self-reported multiple sexual partners among ABYM at 6-month follow-up. No significant changes were noted over a 24-month period in mean number of sexual partners, 1.5 (1.3–1.7) vs. 1.5 (1.3–1.7), p = 0.98, and number of additional non-wife sex partners, 5.4 vs. 5.1, p = 0.98, compared to data prior to the intervention [48]. No significant gender differences were noted in these interventions.

Abstinence

Seven studies measured abstinence (both primary and secondary) with the aim of preventing early sexual debut [27, 28, 30, 32, 35, 43, 45]. Of these, four reported improved secondary abstinence [30, 35, 43, 45]. Although the African Youth Alliance (AYA) intervention reported improved secondary abstinence, the intervention had no effect in delaying sexual initiation among boys [30]. The Zambian Peer Intervention reported changes in beliefs about abstinence rather than in actual abstinence behavior among 14–23-year-old adolescent males and females at 9 month-follow-up [28]. Differential impacts by gender were noted in the Siyakha Nentsha intervention, with boys aged 14–16 years more likely to have remained sexually abstinent at the 18-month follow-up compared to girls of the same age [43]. The No Name intervention reported increased abstinence in both sexes at 3-year follow-up [45]. The PREPARE intervention influenced delaying self-reported sexual initiation among adolescent boys [35].

Intergenerational Sex

The Fataki intervention study measured intergenerational sex [47]. This intervention, which was the only one to measure intergenerational sex, noted no change in intergenerational sex for men exposed to a behavioral campaign more than ten times in the past 3 months (OR 1.11, 95% CI 0.61–2.01, p > 0.05) compared to the non-exposure group.

Alcohol and Drug Abuse

Four intervention studies measured alcohol and drug abuse targeting ABYM with a mean age of 16 years [21, 22, 24, 37]. Two of these were sports-based and reported a decline in substance abuse at 6 months post-intervention, measured using a rapid drug test before each soccer match [22, 37]. Alcohol and drug tests were randomly administered at the beginning of each soccer game. Games were held twice a week with competitive games on weekends. Reductions in alcohol consumption and alcohol-related behaviors were found in the One Man Can intervention [22], whereas less problem drinking was recorded in both sexes in the Stepping Stones intervention [24]. Findings were self-reported and follow-up periods ranged from 6 to 24 months.

Knowledge About HIV/AIDS

Knowledge about HIV and AIDS, including questions on prevention, risk factors and/or misconceptions, was assessed in five studies focusing on ABYM [24, 32, 40, 47, 48]. The average age of participants was 15 years. Improved HIV knowledge, attitudes, perceptions of social support, and HIV prevention knowledge were noted in three of these studies [24, 32, 40], with a differential gender impact in the Mzakhe ndi Mzakhe weekly educational sessions intervention [32], which found that the intervention had no effect on females aged 13–15 years compared to boys of the same age. Follow-up periods were from 6 months to 2 years. All outcomes were self-reported through surveys and group discussions.

Biomedical Outcomes

Biomedical interventions, which encompassed both clinical and medical outcomes, aimed to reduce HIV transmission. These included voluntary male circumcision (VMMC) and HIV counseling and testing.

VMMC

Four intervention studies focused on voluntary medical male circumcision, and all were effective [20, 23, 36, 38]. Results indicated that age was associated with VMMC in two of these studies, with younger participants more likely to undergo circumcision (aOR 2.45, 95% CI 1.24–4.90, p = 0.02) in the Spear and Shield intervention at both 6- and 12-month follow-up [36]. Exposure to education about VMMC was also associated with an increased likelihood of undergoing circumcision in this intervention. The Make the Cut + intervention reported increased VMMC uptake (OR 2.53, 95% CI 1.21–5.30, p = 0.01) compared to the control group [38]. Overall, 40% of participants in the experimental group underwent circumcision compared to 24% of control participants at 12-month follow-up. Outcomes were based on clinical records of circumcisions in both groups.

HIV Testing

Eight studies had outcomes related to HIV testing for ABYM [22, 24, 25, 32, 41, 44, 46, 48]. All of these studies found improvements in HIV testing uptake except the Sahwira intervention which reported no difference in HIV testing uptake pre- and post-intervention [48]. There was improved acceptance of testing as age increased in the PopART for youth study at 12 month-follow-up [44]. Testing was 29.2% before vs. 87.8% after the intervention in Zambia, and 21.3% vs. 77.3% in South Africa, respectively, with no measure of statistical significance provided. In another study, the SASA! intervention, intervention effects were greater in males than in females [41]. For men solely, HIV testing increased (aRR 1.50, 95% CI 1.13–2.00, p < 0.05) after the intervention compared to before. HIV testing outcomes were either self-reported or obtained from clinical records, with follow-up periods ranging from 12 months to 5 years for all studies.

Norm-Changing Outcomes

Eight studies evaluated norm-changing interventions [20, 22, 24, 25, 29, 31, 33, 39], which sought to change attitudes and social beliefs about HIV/AIDS risk. Social environments and social norms that heighten risky sexual behaviors place young men and women at extremely high risk of HIV/STI acquisition and onward transmission. These include stereotypical norms of masculinity, such as multiple sexual partnerships and condoning physical and sexual violence to dominate partners in relationships. Gender norms deter men from accessing health services, resulting in poor uptake of preventive care services, including HIV testing. Of note, males (18–35 years) embraced attitudes for equality with women and perceived their male identity differently in ways that reduce violence against women and intimate partners in three interventions [20, 22, 25]. The interventions had no effect in two studies [25, 39]. There was a marked increase and decrease post-intervention in the proportion of men who believed that men should make final household decisions (50% vs. 38%, p = 0.036) and that women who carry condoms are easy (36% vs. 20%, p = 0.004) compared to pre-intervention, respectively, in the Men as Partners intervention campaign [25]. The combined Stepping Stones and Creating Futures intervention found no evidence of change in men’s controlling behaviors toward women (β = 0.06, 95% CI − 0.51 to 0.63, p = 0.839) [39]. This intervention also found lower odds of interpersonal violence (IPV) post-compared to pre-intervention (aOR 0.71, 95% CI 0.51–0.97, p < 0.001) [39]. Outcomes were measured by means of the Gender-Equitable Men (GEM) Scale in three interventions [22, 29, 31] and validated through police or hospital records of physical or sexual violence committed during the preceding 6 months in three interventions [20, 22, 24] or self-reported in two interventions [25, 39]. Follow-up periods for these studies ranged from 6 months to 3 years.

Livelihood-Strengthening Outcomes

Young people, not formally employed or educated, face exceedingly high levels of IPV and an increased likelihood of engaging in risky social interactions, raising the potential for HIV acquisition. Interventions designed to reduce vulnerability through enhancing livelihoods and financial independence as well as offering social protection have been shown to reduce HIV vulnerability and IPV [54].

Only two interventions had a social protection component, and both reported improved outcomes compared to pre-intervention periods [39, 43]. The Stepping-Stones and creating futures intervention found no improvement in past month earnings savings for both men and women at 24-month follow-up (β = 0.21, 95% CI − 0.42 to 0.83, p = 0.521) [39]. The Siyakha Nenthsa Programme recorded improved budgeting and planning skills in school-going boys and girls (14–16 years) only in the intervention group at 18-month follow-up [43]. Participants were more likely to have attempted to open a bank account when compared to the control group. Men’s self-esteem improved and criminal behaviors were reduced because men were self-sufficient due to the Stepping Stones and Creating Futures intervention [39]. Men reported feeling less shame about lack of work and less stealing in the past week due to hunger.

Discussion

This scoping review examined 29 studies that evaluated sexual risk-reduction interventions in ABYM between the ages of 10 and 24 in nine SSA countries. Our results show that behavioral interventions were moderately successful in improving condom use [22, 24, 26, 27, 36, 41, 42, 45]. However, the review also showed that sexual risk-reduction interventions (especially those including condom promotion) could encourage multiple sexual partnerships, thereby increasing HIV transmission risk. For example, the Condom Technical Skills intervention improved condom use, while simultaneously increasing multiple partner sexual activity among participants [27]. This spike in multiple partnership sexual activity may have been brought about by an over-reliance on condom safety, while neglecting related aspects of sexual behavior (frequency of sex, number of sex partners—multiple and concurrent). The more partners one has, the greater the odds of acquiring HIV. Condoms may help in ensuring safety, but this is only applicable when they are used correctly and consistently.

This review found that interventions had a positive effect on the reduction of multiple sex partners [20, 22, 24, 28, 41, 45]. However, in the interventions included in this review, sustaining such a positive outcome was a challenge. One study showed an increase in multiple sex partners post-intervention, possibly indicating neglect in tackling normative drivers that underpin sexual risk practices [27].

In addition, the review highlighted a differential impact across gender. The Healthwise program found that boys had greater condom use self-efficacy than girls both at baseline and throughout the study [34]. Differences may be because 8th-grade lessons taught skills such as decision-making and negotiation which might appeal more to girls, whereas 9th-grade lessons focused on condom use within sexual relationships which might be more salient to boys than girls. However, the African Youth Alliance intervention substantially increased condom use, consistency of condom use, and contraceptive use among female but not male participants [30].

Although the above results are gender-specific, mixed-gender intervention approaches should be adopted. Their strength lies in their ability to enable ABYM to engage with AGYW to explore and reframe gender and sex roles, assumptions, and decision-making in a safe, structured setting [39]. Findings also suggest the importance of introducing topics in sex-segregated groups because men and women in the early phases of sex most likely engage with different levels of sexual awareness; thus, gender-specific interventions may be appropriate, at least initially. For instance, girls often report earlier sexual debut than boys [55]; therefore, program goals for men and women should not overlap at different developmental stages [56]. Welbourn also favors such an approach, pointing to the usefulness of engaging existing culturally defined community groups, generally divided along gender and age lines, which allows each group to have safe private time and space to explore their own concerns [57].

Male-specific positive outcomes emphasized the potential of brotherhood bonds to initiate change which opened up spaces to discuss men’s harmful sexual practices while trying to restore a sense of dignity among men [23]. Through such interactive and communicative group spaces, participants constructed messages and meanings of their social realities, with the potential for transformation toward healthy masculine attitudes. As noted by Figueroa and colleagues, the ideal model of development communication is one “based on dialogue versus monologue, horizontal versus vertical information sharing, equitable participation, local ownership, empowerment, and social versus individual change” [23]. In other words, interventions should be tailored to the target population with their participation and input to optimize their success.

Interventions are likely to be most effective when they are age-appropriate and tailored to the cognitive level of the adolescent. More specifically, Spear and Shield found that younger participants were more likely to undergo circumcision compared to their older peers [36]. However, in the Make the Cut + intervention, there was evidence of increased uptake of VMCC with age in both study arms [38]. Even though the above findings seem contradictory, other research indicates that sexual risk-reduction interventions that generally target pre- or early adolescence, irrespective of the focal outcome, produce more positive outcomes than those targeting late adolescence [58]. Targeting pre- or early adolescence for sexual risk-reduction interventions is also more feasible because a significant proportion of young people are less likely to have initiated sex at this stage [58].

Interventions included in the review have also shown to be effective in improving attitudes and norms [20, 22, 25, 39]. Norms have long been recognized as critical barriers to HIV prevention behaviors. Addressing gender inequalities may reduce young men’s perpetration of gender and sexual violence and encourage young men to engage in protected sex [25]. Combined with livelihood-strengthening outcomes, intervention effects may be bolstered. For example, the It’s Our Futures Too intervention (a combination intervention approach) noted significant and positive differences in financial independence, overall HIV knowledge, self-efficacy related to abstinence and condom use, and knowing one’s own HIV status between the intervention and control groups [46]. These findings support recent evidence from Uganda suggesting that a combination social protection response may be more effective than unidimensional programming [59, 60]. A successful intervention is more likely to have compounding and synergistic effects in reducing HIV transmission below the reproductive rate necessary to achieve HIV epidemic control [61,62,63].

Interventions that entail the use of friendship networks show promise in influencing peer norms and behavior among ABYM both in- and out-of-school. Boys create and seek out spaces among their male peers from which to cultivate their masculinities through heterosexual discourses, including being ‘at risk’ of getting HIV [64]. The success of Stepping Stones was clearly associated with peer-to-peer education aimed at gender transformational change and HIV risk-reduction behaviors, particularly among men, when offered viable alternative normative behaviors [24]. The Stepping Stones and creating futures study showed reductions in IPV-see Gibbs et al. [34]. The Brother’s for Life intervention also reached men in their interactive group/friendship networks and showed some positive trends toward reducing rape and domestic violence through enforcing positive norms and reducing concurrent sexual partnerships [20].

More generally, a peer network approach emphasizes the potential of brotherhood bonds to initiate change, opening spaces to discuss men’s relations with their intimate partners, while trying to restore their sense of dignity [23]. Through such interactive and communicative group spaces, ABYM can construct messages and meanings of their social realities, with the potential for transformation to adopting healthy attitudes and behaviors.

Outcomes from this review suggest that although communication channels, such as the media (TV, newsprint, billboards), can perpetuate harmful gender norms, they also can be potential avenues for shifting attitudes, norms and behaviors. The Brothers for Life intervention [20] and Grassroots intervention [40] used highly innovative, action-oriented group-based activities such as warm-up games, role-plays, radio and TV discussions, and brainstorming. These interventions reported improvements in HIV prevention knowledge and correct and consistent condom use.

Although structural interventions are often critiqued as ‘social development’ rather than focused health interventions [65], this review showed how such interventions can alter the context of young people’s HIV risk through improving personal agency. The Siyakha Nentsha intervention found increased autonomy around financial decision-making [43]. Boys in the intervention group were more likely to have remained sexually abstinent between survey rounds, and those who did have sex reported fewer sexual partners than boys in the control group.

Use of facilitators who are well-regarded to disseminate messages contributed to intervention success. In the Learning Centre Initiative, religious leaders contributed to the intervention’s success, noteworthy given that religion could also be an impediment to sexual health promotion [33]. The Brothers for Life Campaign used soccer celebrities and coaches who were perceived as displaying upstanding behavior as trusted trendsetters whose actions, attitudes, and views influenced their peers [20]. In the Champions League intervention, use of same-sex facilitators as well as peer counselors proved beneficial as participants felt comfortable discussing personal issues with members of the same sex [37].

Program sustainability, “the ability to maintain programing and its benefits over time” [66] beyond the intervention period was an issue in the studies reviewed. Many interventions could not be sustained after implementation. For example, the Zambian Peer Intervention found changes in normative beliefs about abstinence, but these changes could not be sustained 6 months after the intervention. Maintaining effective programs and practices is critical for achieving health benefits for the intended population in which positive change is desired [36].

Strengths and Limitations of the Scoping Review and Studies Reviewed

The strength of this review is that it covered a period of 20 years of published studies focusing on ABYM populations in- and out-of-school in SSA. The review focused on studies using a variety of methodologies in different settings and identified interventions that showed both positive and negative outcomes (reducing sexual risk behaviors and associated attitudes and norms) using different measures. Additional studies that included young males might have been missed in our search for several reasons. We excluded interventions from the review if study results were not stratified by age and/or sex. Some studies that included age and sex in their analysis were ultimately excluded for failing to specifically report intervention outcome effects in young adult males. Analysis of intervention findings by age and gender sub-groups is critical to better reflect the diversity in risk behaviors among ABYM.

A key weakness of many studies in the review is the reliance on self-reported measures of behavior change. Self-reported outcomes reduce confidence in demonstrating intervention efficacy. When self-reported data and biomarkers are readily available and easy to collect, a combination of these measures is recommended as a reliable representative of sexual risk behavior [67].

There were few commonalities in the study designs of interventions in this review (type and content), perhaps suggesting little consensus on the optimal approach to evaluating these interventions. Out of the 29 studies included in the review, only 14 were randomized trials. Future interventions need to adopt a more rigorous methodology in the design and measurement of risk behaviors. Using outcome measures that are standard across trials may permit a more uniform comparison of interventions.

Interventions in this review included both in- and out-of-school interventions. Schools are an ideal place to reach ABYM because this is where they are likely to receive appropriate sexuality information and education. Although in-school interventions may be feasible and cost-effective, out-of-school interventions are equally important because this ABYM population may be more vulnerable and exposed to sexual risk-taking behavior. Out-of-school interventions can target ABYM through informal community programs, e.g., street theater and music. Interventions such as Sonke Gender Justice’s One-Man Can and Engender Health’s Men as Partners (MAP) targeted ABYM through informal community programs [22, 25].

Studies included in the review highlighted the paucity of structural interventions, specifically those with an economic link such as cash transfers. Only the Stepping Stones and Creating Futures intervention had an economic element [39]. The remaining were norm-based interventions. As such, there is need for interventions to adopt structural approaches that can alter the context of young people’s HIV acquisition through economic empowerment initiatives as well as those that change the social and political contexts that influence the drivers or mediators of HIV.

Several studies based their interventions on behavioral theories and models, e.g., the Health Belief Model [30], Social Learning [20, 32, 38, 40] and Theory of Reasoned Action [32]. These theories have been criticized for being simplistic and reductionist in their analysis of sexual behavior [12, 13] as they do not consider the contextual and structural determinants of sexual behavior. Working with reductionist theoretical frameworks can lead to limited effective intervention outcomes. Developing more explicit links between theories of HIV risk and possible intervention pathways toward behavior change in different HIV contexts and populations would be an important step for future research.

Sustained behavior change also remains a challenge in the interventions reviewed. There is a need to identify and describe existing facilitators or barriers to outcomes to better understand implementation processes, promote the use of impactful interventions, and advance the field of dissemination and implementation science. Lack of appropriate conceptualization of interventions from the outset compromises program sustainability.

Conclusion

This review indicates that sexual-risk interventions engaging ABYM in SSA show some promise and identifies ways to build and strengthen good practices, particularly those that encourage combination-type sexual risk-reduction interventions (biological, behavioral and structural components). The review found a positive impact of interventions on condom use, reduction of multiple sexual partners, abstinence, alcohol and drug abuse, and HIV testing as well as livelihood-strengthening interventions. Where gender, age and grade variables were employed in study designs, effects were mixed. Future studies need to pay more attention to these variables when designing and evaluating interventions. However, where interventions showed positive evidence of reducing risky sexual behaviors, change was not sustained. Future interventions require more longitudinal studies (including a qualitative and process-level methodology) to document why health behaviors may not be sustained in specific contexts post-intervention. Engaging ABYM in HIV prevention interventions should occur in ways that do no harm, but promote gender and sexual diversity, equality, and health for all.