The quality of research examining HIV prevention programmes targeted at young people in Africa is poor, according to the authors of a systematic review and meta-analysis published in the online edition of AIDS.
Moreover, evidence that such prevention programmes had an effect was limited and confined to sub-groups.
“Surprisingly little information was available on youth interventions in sub-Saharan Africa: only 28 studies were identified with as few as two studies collecting biological endpoints, and many studies had suboptimal design”, write the investigators.
Young people are one of the focuses of the HIV pandemic. In South Africa, 4% of young women aged between 15 and 24 are HIV-positive, with 2% of men in this age group also having HIV infection.
A large number of prevention programmes are targeted at younger people with the aim of reducing their sexual risk behaviour.
It’s important to know if these interventions work. Therefore, investigators conducted a systematic review and meta-analysis to assess the effectiveness of prevention programmes for the young. They noted, “this is the first meta-analysis of the impact of behaviour interventions for youth in sub-Saharan Africa.”
To be included in the review, the studies had to have a control group, focus on young people (ages 10 to 25), have been undertaken after 1990, and report on the behavioural interventions aimed at preventing HIV transmission by reducing sexual risk taking.
The investigators search identified 758 articles. However, only 31 studies reporting on 28 interventions met the investigators' inclusion criteria.
Eleven of these studies were randomised trials, 15 used a cross-sectional design, and 13 were cohort studies.
Most (16) were conducted in schools, eight were undertaken in the community, and four in both schools and the community. The duration of interventions ranged from one hour to three years.
Outcome measures included condom use, behavioural change, and biological outcomes such as infection with HIV or a sexually transmitted infection.
Condom use
A total of 18 studies measured condom use. Their results were highly variable. Generally, the interventions had a greater impact on condom use by males than females.
In the meta-analysis, condom use was 46% higher during last sex among the males who received the intervention than those who did not. Interventions also increased general condom use amongst young men (RR = 1.32; 95% CI, 1.25 to 1.40).
Three studies examined participants’ intention to use condoms. One study had a positive effect, one had negative results, and the intervention in the third study had no impact at all.
Sexual behaviour
The most common measure of sexual behaviour (eleven studies) was ever having sex. Generally, there was no evidence that participation in HIV prevention programmes increased sexual activity.
Sexual abstinence was examined in three studies. Reported rates increased in two of these, but fell in the third.
Recent sexual activity was evaluated in seven studies. One study found a reduction, whereas three identified an increase.
Information was nine studies were available on their effects on multiple sexual partnerships. Once again, there was little evidence that these increased amongst those who received the HIV prevention intervention. In the five studies where the intervention was successful, in three the effects were more pronounced in young men than young women.
Biological outcomes
Only two studies examined biological outcomes. Rates of HSV-2 were lower in the intervention group in a South African study, but the intervention had no impact on the incidence of HIV or pregnancy.
A Tanzanian study also showed that the intervention had no impact on rates of HIV or pregnancy.
The investigators express their surprise and concern about the paucity of high quality studies examining the effectiveness of HIV prevention interventions for young people in Africa. They write, “this is particularly concerning given the extent of the vulnerability of HIV infection faced by the 125 million young people in sub-Saharan Africa, and the presence of numerous HIV prevention initiatives and funding opportunities in the region.”
Moreover, the investigators note that there was little consistency in the prevention approaches of the studies they identified and that few “have built upon previous knowledge in a linear fashion. In addition, no two studies used the same methods of analysing or reporting data, and outcome indicators very markedly diverse.”
They therefore recommend that “there should be more studies that use a strong evaluation design and measure biological outcomes.”
As regards the outcome of the studies, the investigators found it “encouraging” that interventions did not increase sexual risk-taking. They comment, “the effectiveness of HIV prevention interventions on sexual behaviour overall, to date, however, appears relatively small”.
Michielsen K et al. Effectiveness of HIV prevention for youth in sub-Saharan Africa: systematic review and meta-analysis of randomized and nonrandomized trials. AIDS, online edition, DOI: 10.1097/QAD.0b13e3283384791, 2010.