Many abstinence-plus programs seem to reduce short-term and long-term HIV risk behavior among youth in high-income countries, according to the results of a systematic review in the January 23 issue of the Cochrane Database of Systematic Reviews.
“Abstinence-plus interventions promote sexual abstinence as the best means of preventing acquisition of HIV, but also encourage safer sex strategies (eg condom use) for sexually active participants,” write K. Underhill, from the University of Oxford, Oxford, United Kingdom, and colleagues. “To date, there has been no systematic analysis of the effects of abstinence-plus programs on HIV prevention among all residents of high-income countries. This review seeks to identify, synthesize, and evaluate the effects of abstinence-plus interventions on HIV-risk behavior and HIV transmission among participants in high-income countries.”
The review authors searched 30 electronic databases through February 2007, including CENTRAL, PubMed, EMBASE, AIDSLINE, and PsycINFO, as well as references cited in identified articles. They also performed a manual search of the literature and contacted experts to identify additional citations.
Inclusion criteria for the review were randomized and quasi-randomized controlled trials evaluating abstinence-plus interventions in high-income countries, as defined by the World Bank. Abstinence-plus interventions were defined as those that promoted sexual abstinence as the best means of HIV prevention but that also encouraged safer sex practices. Evaluated endpoints were self-reported biological and behavioral outcomes and knowledge of HIV infection.
Three reviewers independently evaluated 20,070 citations and 325 full-text papers to determine if they met inclusion criteria (39 studies), as well as for methodologic quality. Heterogeneity and missing data precluded meta-analysis, so study results were presented individually.
Participants in these studies were 37,724 ethnically diverse North American youth. The abstinence-plus interventions were administered in 10 schools, 24 community facilities, both schools and community facilities in 2 studies, 2 healthcare facilities, and 1 family home. Median duration of follow-up was 12 months from baseline.
Findings of the included trials offered no evidence that abstinence-plus programs can affect the incidence of self-reported sexually transmitted infection (STI) and limited evidence that these programs can decrease the incidence of self-reported pregnancy.
For behavioral outcomes, the findings were more encouraging. Of 39 evaluations, 23 showed a significantly protective effect of the intervention for at least 1 behavioral outcome, and effects of the intervention were consistently favorable for HIV knowledge. There were no adverse effects associated with abstinence-plus interventions. In several evaluations, 1 version of an abstinence-plus program was shown to be more effective than another, indicating that additional research into intervention mechanisms may be warranted.
Methodologic strengths of the included trials were large sample size and use of statistical controls for baseline values, whereas weaknesses included underuse of relevant outcomes, self-report bias, and failure of analyses to consider attrition and clustered randomization.
“Many abstinence-plus programs appear to reduce short-term and long-term HIV risk behavior among youth in high-income countries,” the review authors write. “Evidence for program effects on biological measures is limited. Evaluations consistently show no adverse program effects for any outcomes, including the incidence and frequency of sexual activity. Trials comparing abstinence-only, abstinence-plus, and safer-sex interventions are needed.”
Potential biases in the review process may have resulted primarily from the search strategy. These include publication bias; possible failure to identify all additional unpublished evaluations of abstinence-plus programs; inability to identify evaluations of abstinence-plus programs focused exclusively on pregnancy or general STI prevention; difficulty in determining the extent to which interventions emphasized abstinence or how they discussed condom use and/or other safer sex strategies; and inability to obtain relevant missing data, including methodologic characteristics, clinical characteristics, and outcome data.
“When compared to a variety of control groups, a number of abstinence-plus programs had significantly favorable effects on sexual behavior outcomes at short-term, medium-term, and long-term,” the review authors conclude. “Consistently protective program effects were observed for the acquisition of HIV/AIDS knowledge at every follow-up point. Several program strategies for high-risk groups appeared to have significantly favorable effects on multiple sexual behaviors, prompting further investigation and potential scale-up of these interventions.”
Internal sources of support were the Centre for Evidence-Based Intervention and the Department of Social Policy and Social Work, Oxford University, United Kingdom. The review authors have disclosed no relevant financial relationships.
Cochrane Database Syst Rev. Published online January 23, 2008.
Clinical Context
In the absence of an effective vaccine against HIV, other means of prevention must be evaluated and implemented. According to the World Health Organization, approximately 1.6 million people in high-income countries, as defined by the World Bank, had HIV infection in 2004, but by 2005, 2.0 million people in North America, Western Europe, and Central Europe alone had HIV infection, and 65,000 became newly infected.
In many high-income countries, sexual behavior is the primary means of HIV infection. US studies have shown that more than 70% of HIV-positive men and women remain sexually active, and a significant proportion of this group continues to engage in unprotected sex. Abstinence-based programs promote sexual abstinence as the best means of HIV infection prevention; abstinence-plus interventions use a hierarchical approach to promote sexual abstinence as the best or safest behavior choice, and then safer sex, to prevent HIV infection. The purpose of this systematic Cochrane review was to identify and evaluate the effects of abstinence-plus interventions on HIV risk behavior and HIV transmission among participants in high-income countries.
Study Highlights
- The review authors searched 30 electronic databases through February 2007, including CENTRAL, PubMed, EMBASE, AIDSLINE, and PsycINFO.
- Other sources for relevant studies were cited references, a manual search of the literature, and contacts with experts.
- Inclusion criteria for the review were randomized and quasi-randomized controlled trials evaluating abstinence-plus interventions vs various control groups in high-income countries, as defined by the World Bank.
- Abstinence-plus interventions, primarily targeting youth, were defined as those that promoted sexual abstinence as the best means of HIV prevention but that also encouraged safer sex practices for those who were not abstinent.
- Endpoints were self-reported biological and behavioral outcomes and knowledge of HIV.
- 3 reviewers independently evaluated 20,070 citations and 325 full-text papers and identified 39 studies that met inclusion criteria and reviewed methodological quality.
- Despite an extensive international search, all included studies took place among youth in the United States, Canada, and the Bahamas. Participants were 37,724 ethnically diverse North American youth.
- Heterogeneity of methods and outcomes and missing data precluded meta-analysis, so study results were presented individually.
- The abstinence-plus interventions were administered in 10 schools, 24 community facilities, both schools and community facilities in 2 studies, 2 healthcare facilities, and 1 family home.
- Median duration of follow-up was 12 months from baseline.
- Biological outcomes were underused and were limited to participants’ self-reported incidence of STI and pregnancy.
- Findings of the included trials offered no evidence that abstinence-plus programs can affect the incidence of self-reported STI.
- Evidence was limited that abstinence-plus programs can decrease the incidence of self-reported pregnancy.
- Of 39 evaluations, 23 showed a significantly protective effect of the intervention for at least 1 behavioral outcome at short-term, medium-term, or long-term follow-up.
- Effects of abstinence-plus interventions were consistently favorable for improving knowledge of HIV infections.
- There were no adverse effects associated with abstinence-plus interventions and no apparent adverse effect on increasing the incidence and frequency of sexual activity.
- Results for outcomes relevant to abstinent behavior (sexual initiation; and incidence and frequency of vaginal, oral, and anal sex) were mixed, suggesting that many, but not all, abstinence-plus programs may reduce the incidence or frequency of sexual activity.
- No study observed an adverse program effect on condom use.
- Several evaluations suggested that 1 version of an abstinence-plus program was more effective than another, warranting additional research into intervention mechanisms.
- Strengths of the included trials were large sample size and use of statistical controls for baseline values; weaknesses were underreporting of relevant outcomes, self-report bias, and failure of analyses to consider attrition and clustered randomization.
- Based on their evaluation, the reviewers concluded that many abstinence-plus programs seem to reduce short-term and long-term HIV risk behavior among youth in high-income countries but that evidence is limited for program effects on biological measures.
- Potential biases in the review include publication bias, possible failure to identify all evaluations of abstinence-plus programs or of those focused exclusively on pregnancy or general STI prevention, difficulty in determining the extent to which interventions emphasized abstinence vs safer sex strategies, and inability to obtain relevant missing data.
Pearls for Practice
- Abstinence-plus programs seem to reduce short-term and long-term HIV risk behavior among youth in high-income countries. Effects of abstinence-plus interventions were consistently favorable for improving knowledge of HIV infections.
- Evidence was limited that abstinence-plus programs can decrease the incidence of self-reported pregnancy, and there was no evidence that abstinence-plus programs can affect the incidence of self-reported STI.
