Background Abstinence-plus interventions promote sexual abstinence as the best means of preventing acquisition of HIV, but also encourage safersex strategies (eg condom use) for sexually active participants. Objectives To assess the effects of abstinence-plus programs for HIV prevention in high-income countries. Search strategy We searched 30 electronic databases (eg CENTRAL, PubMed, EMBASE, AIDSLINE, PsycINFO) ending February 2007. Cross-referencing, hand-searching, and contacting experts yielded additional citations. Selection criteria We included randomized and quasi-randomized controlled trials evaluating abstinence-plus interventions in high-income countries ( as defined by the World Bank). Interventions were any efforts that encouraged sexual abstinence as the best means of HIV prevention, but also promoted safer sex. Results were self-reported biological outcomes, behavioral outcomes, and HIV knowledge. Data collection and analysis Three reviewers independently appraised 20070 citations and 325 full-text papers for inclusion and methodological quality; 39 evaluations were included. Due to heterogeneity and data unavailability, we presented the results of individual studies instead of a meta-analysis. Main results Studies enrolled 37724 North American youth; participants were ethnically diverse. Programs took place in schools ( 10), community facilities ( 24), both schools and community facilities ( 2), healthcare facilities ( 2), and family homes ( 1). Median final follow-up occurred 12 months after baseline. Results showed no evidence that abstinence-plus programs can affect self-reported sexually transmitted infection (STI) incidence, and limited evidence that programs can reduce self-reported pregnancy incidence. Results for behavioral outcomes were promising; 23 of 39 evaluations found a significantly protective intervention effect for at least one behavioral outcome. Consistently favorable program effects were found for HIV knowledge. No adverse effects were observed. Several evaluations found that one version of an abstinence-plus program was more effective than another, suggesting that more research into intervention mechanisms is warranted. Methodological strengths included large samples and statistical controls for baseline values. Weaknesses included under-utilization of relevant outcomes, self-report bias, and analyses neglecting attrition and clustered randomization. Authors' conclusions Many abstinence-plus programs appear to reduce short-term and long-term HIV risk behavior among youth in high-income countries. 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.
