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HIV Prevention Knowledge Base

A Collection of Research and Tools to Help You Find What Works in Prevention

Behavioral Interventions: Comprehensive Sexuality Education

I. Definition of the Prevention Area

Young people in many countries have unprotected sexual intercourse with one or more partners, potentially exposing themselves to HIV, other sexually transmitted infections (STIs), or unintentional pregnancy. Comprehensive sexuality education (CSE) programs work to delay initiation of sex, reduce the number of sexual partners, and increase the use of condoms and other forms of contraception. Some programs also seek to increase testing and treatment for HIV and other STIs. They can be implemented both in schools and in other community settings.

II. Epidemiological Justification for the Prevention Area

The global HIV epidemic cannot be reversed without sustained success in reducing new infections. The proportion of new HIV infections attributed to young people varies greatly across countries and by type of epidemic. A recent United Nations Children’s Fund report estimates that young people aged 15 to 24 accounted for 41 percent of all new HIV infections in adults in 2009. This represents an estimated 5 million young people. In sub-Saharan Africa, nearly 3.3 million youth are living with HIV. Globally, young women make up more than 60 percent of all young people living with HIV; in sub-Saharan Africa, their share jumps to 72 percent.

Young people can reduce their chances of contracting HIV if they reduce their sexual risk by, for example, delaying sex, reducing the number of partners they have, avoiding sex with older partners and with people having concurrent partners, increasing condom use, and, for uncircumcised men, undergoing voluntary medical circumcision. There is strong evidence that CSE programs with certain core programmatic components can reduce sexual risk by changing some of these behaviors. When these programs are implemented in schools, they can reach very large numbers of young people before and after they begin having sex. They can also reach out-of-school youth in clinics, other youth-serving organizations, and communities more generally.

III. Core Programmatic Components

Some CSE programs have reduced sexual risk-taking, while others have not. Effective programs incorporate 24 core characteristics in their development and implementation. For example, they involve experts in behavior change theory and research, involve young people in the design of the program, use a clear logic model, focus on specific behavioral goals and specific cognitive factors that affect those behaviors (e.g., knowledge, perception of risk, values, attitudes, peer norms, skills, intentions), employ multiple participatory activities that address those cognitive factors, give clear messages about behavior, implement at least 12 sessions (if in schools), and provide training to educators.

IV. Current Status of Implementation Experience

Close to 100 studies have examined the impact of CSE programs around the world. These studies include strong quasi-experimental or experimental designs. Their results support several conclusions about the impact of CSE programs:

  • A third or more of these programs delayed sex, reduced frequency of sex, reduced number of partners, increased condom use, increased overall contraceptive use, or reduced unprotected sex.
  • Almost two-thirds had a desired impact on one or more of these sexual behaviors.
  • None increased any measure of sexual activity.
  • Virtually all programs that incorporated the core components had significant desired effects on behavior.
  • Their positive impact on behavior is modest, but programmatically meaningful.

If implemented on a large scale, effective CSE programs represent a cost-effective method of changing behavior and thus can serve as an important component within comprehensive initiatives to reduce HIV, other STIs, and unintended pregnancy.