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Many adolescents engage in sexual intercourse with multiple partners and without condoms. Thus, they engage in sexual behaviors that place them at risk of sexually transmitted diseases (STDs), including HIV. Among sexually experienced people, adolescents aged 15 to 19 years have some of the highest reported rates of STDs. In addition, particular groups of adolescents (eg, males who have sex with males, injection drug users, and teens who have sex for drugs) engage in even greater risk-taking behavior. Consequently, an estimated 25% of all people with HIV in the United States contracted HIV when they were teenagers.(1,2) Accordingly, professionals concerned with adolescents have developed school and community programs to reduce adolescent sexual risk-taking behavior. Some of these programs have been effective at changing behavior, while others have not.

This chapter presents data on adolescent sexual risk-taking behavior, reviews the studies measuring the impact of adolescent prevention programs, and identifies common characteristics of programs that have been effective in reducing sexual risk-taking behavior. It recommends a) that these effective school and community programs be implemented more broadly, b) that promising clinic programs and comprehensive community-wide campaigns be replicated and evaluated, and c) that additional programs focusing on high-risk youth be implemented and evaluated.

In many countries throughout the world, sexually transmitted disease and unplanned pregnancy have always occurred among adolescents. However, during the last century, and especially during the last few decades of that century, the onset of puberty and initiation of sexual intercourse occurred at decreasing ages in many industrialized countries, whereas the average age of marriage increased. Thus, many adolescents began having sexual intercourse with multiple sexual partners prior to marriage, and this, of course, facilitated STD and HIV transmission. In many countries, a significant proportion of young people initiate sexual activity by age 15.

Among students in grades 9-12 across the U.S. in 2001, 46% reported ever having had sexual intercourse. About 61% reported having sex before they graduated from high school.(3) Although most teenagers practice serial monogamy and do not have sexual intercourse with more than one sexual partner during any given period of time, their numbers of sexual partners do add up over time. Among U.S. high school seniors in 2001, about 22% had had sexual intercourse with four or more sexual partners.(3)

The impact of having sex and especially of having multiple partners is somewhat diminished by the fact that most Americans, including adolescents, have sexual partners within social networks. These networks are often defined by ethnicity, class, geographic location, and other socially defined norms. Sometimes these networks do not connect with each other.(4) Consequently, some STDs are limited to particular social networks, and HIV, for example, is not rapidly spreading from one network to another in the adolescent population.

Condoms are recognized as an especially important form of contraception, because they are currently the only form of contraception that prevents the transmission of most STDs.

Among sexually active students in grades 9-12 in 2001, 58% reported using a condom the last time they had intercourse.(3) This percentage is two to three times higher than those reported in the 1970s before AIDS became a public issue.(5) This increase over time suggests that the emergence of AIDS and public campaigns to prevent AIDS through increased condom use have actually increased condom use.

However, condom use varies with urban area, age, ethnicity, gender, and involvement in other risk-taking behaviors, and this national average obscures wide variations in different groups. In young people, for example, condom use declines with age, and is higher among African-Americans than European-Americans.(3)

Although many adolescents have used a condom at some point in time, comparatively few use them during every act of intercourse. In 1995, only 44% of 15- to 19-year-old males used a condom during every act of intercourse during the previous 12 months.(6)

STDs are a significant public health concern, and their significance is further increased by their contribution to HIV transmission. According to some estimates, both ulcerative and nonulcerative STDs increase HIV transmission risks as much as 3- to 5-fold.(7) And, of course, STDs are transmitted by unprotected sex that can also lead to HIV transmission.

About 3 million teenagers acquire an STD every year in the United States.(8) This represents roughly one in eight young people between the ages of 13 and 19, and about one in four of those who have ever had sexual intercourse. In addition, about 25% of all young people are infected by any STD by age 21.(9) Approximately a quarter of all reported cases of STDs occur among teenagers.(10) Globally, over 100 million STDs occur each year in people who are younger than 25 years old.(11)

Adolescents have the highest age-specific rates for some STDs.(12) For example, teenagers have the highest rates of chlamydia.(13) Among sexually active 15- to 19-year-old females in the United States, rates of chlamydia infection are consistently higher than 5% and are often above 10%.(10) As a result, 40% of all reported chlamydia cases are among 15- to 19-year-old youth. Similarly, female teenagers have the highest age-specific rate of gonorrhea, whereas male teenagers have the third highest rate.(13)

Globally, an estimated 11.8 million young people aged 15-24 were living with HIV by mid-2002. About half of all new HIV infections worldwide, or approximately 6,000 per day, occur among young people.(14) The United Nations General Assembly Special Session on HIV/AIDS (UNGASS) established the goal of reducing HIV prevalence among young men and women aged 15 to 24 by 25% in the most affected countries by 2005, and by 25% globally by 2010.(15)

Because many HIV-infected adolescents and young adults have not been tested for HIV and their HIV status is not known, and also because of the typically long latency period before development of clinical AIDS, many cases of HIV/AIDS that are identified among people in their 20s or even early 30s may have been acquired during their teen years or in their early 20s.

Despite the challenges of determining at what ages HIV infection occurs, the U.S. Office of National AIDS Policy has estimated that half of all new HIV infections occur in people under 25 and that half of these occur among young people between the ages of 13 and 21. Among adolescents aged 13-21, older adolescents, males, and members of racial minorities have the highest infection rates.(1)

Among new cases of HIV infection reported among 13- to 24-year-old men in the United States in 2001, 48% were among men who have sex with men, 3% were among men who injected drugs, another 3% were among men who both had sex with men and injected drugs, and only 6% were among men who were exposed through heterosexual contact.(2) Among new cases of HIV reported among young women aged 13-24 years, the exposure category with the largest number of cases was heterosexual contact (33%). Among both males and females, the risk category was often unidentified.

Adolescents, in general, are at risk of contracting HIV through sexual transmission, because a large majority engage in sexual intercourse, have multiple partners over a period of time, and fail to consistently use a condom during every act of intercourse. In addition, many young people also become infected with other STDs that facilitate the transmission of HIV. On the other hand, in the United States, most of these adolescents are actually at relatively low risk, because they rarely, if ever, have sex with people who are HIV infected.

In contrast, adolescents in countries where HIV infection is widespread are at much higher risk of contracting HIV through sexual intercourse, as are adolescents in low-prevalence countries who have unprotected intercourse with members of very high-risk groups (eg, males who have sex with other males or injection drug users). In addition, there are some adolescents who engage in very frequent unprotected sex for drugs, and thereby greatly increase their risk, both by having frequent unprotected sex and by having sex with partners in high-risk groups. These high-risk groups are somewhat bounded by social networks, but this may change. Finally, some adolescents are at risk of contracting HIV through sharing needles used to inject drugs.

These patterns have important implications for educational programs. First, they suggest that there should be effective HIV education programs for all young people. Furthermore, they suggest that there should be additional, more focused programs targeting those groups of adolescents who are at higher risk of HIV infection. Educational programs for school-aged males should adequately address the risks of unprotected intercourse among males who may have sex with males, while programs for young women and female adolescents in the United States should address the special threat of unprotected heterosexual intercourse with injection drug users and the exchange of sex for drugs. Finally, programs should address drug use and needle sharing.

Programs for some of those subgroups of young people who are particularly at risk (eg, males who have sex with males, injection drug users, and racial minorities), are discussed in separate chapters. The remainder of this chapter reviews programs designed to reduce sexual risk-taking among adolescents in general in the United States.

In the United States, sex, STD, and HIV education programs have been implemented in a variety of settings including schools, family planning clinics, STD clinics, churches, youth serving agencies, housing projects, homeless shelters, detention centers, and communities more broadly. In addition, programs have tried to reach parents and their adolescent children in their homes, whereas others have used social marketing and media approaches.

As long ago as the early 1900s there was concern that young people were having premarital sex and that the rates of "venereal disease" (VD) were increasing. Believing that accurate information about VD would prevent youth from engaging in sex, some schools and community organizations implemented VD education programs.(16)

However, many more schools began developing programs to address adolescent sexuality during the 1970s when adolescent sexual behavior, unintended pregnancy, STDs, and their consequences were better measured and publicized. Schools responded far more dramatically when AIDS became a prominent problem in the latter part of the 1980s. The advent of AIDS affected both the willingness of some schools to cover certain topics and the overall design of some programs.

Thirty-eight states require that schools offer STD/HIV education.(17) Consistent with this, a 1999 national survey of school teachers in grades 7-12 revealed that about 93% of their schools offered sexuality or HIV education.(18) Of those schools teaching any topics in sexuality education, between 85% and 100% included instruction on consequences of teenage parenthood, STDs, HIV/AIDS, abstinence, and ways to resist peer pressure to have sex. In 2001, 89% of the students in the national Youth Risk Behavior Survey reported that they had been taught about AIDS/HIV in school.(3)

Throughout the United States, there has been and continues to be widespread support for sexuality and HIV education in schools. For example, four national Gallup polls conducted between 1981 and 1998 revealed continual increases from 70% in 1981 to 87% in 1998 of American adults who believed that public high schools should include sex education in their instructional programs.(19) Similarly, a 1999 Hickman-Brown national opinion poll found that 93% of adults supported sexuality education in schools.(20) Widespread support extends to education on topics such as condoms (90%) and other forms of contraception (87%). Because of this support, some sex and HIV education programs are implemented with relatively little controversy.

On the other hand, there are sex and HIV education controversies in many other communities and entire states. Often these controversies focus on whether only abstinence should be taught in schools or whether condoms and other forms of contraception should also be discussed. In some communities, proponents of abstinence-only approaches are willing to discuss condoms and other forms of contraception, but only if their failure rates are emphasized. Other groups believe that condoms and contraception should be covered in a medically accurate manner.

As a result of these controversies, an increasing number of states place restrictions on instruction about condoms and contraceptives, and a substantial proportion of schools limit instruction to abstinence. According to a large national study of school district policies, of the 69% of school districts that have policies on sex education, 35% teach abstinence as the only option outside of marriage, and either prohibit instruction on condoms or contraceptives or focus upon their shortcomings.(21)

Proponents of more balanced and comprehensive discussion of condoms and contraception are more likely to have such programs implemented when they: a) document the sexual activity of the students or adolescents in the targeted community, b) document student and parent support for such approaches, c) involve parents and community leaders in the design and development of the program, and d) listen thoughtfully to opponents and try to accommodate their concerns as much as possible without sacrificing instruction on proper use of condoms. Other strategies can also facilitate the design and acceptance of more comprehensive programs.(22,23)

During the 1990s, high schools began making condoms available to students as part of their HIV/AIDS prevention programs. Condoms are widely available in schools in some of the largest U.S. cities, such as New York City, Los Angeles, and Philadelphia; they also are available in many smaller cities such as Falmouth, MA; Commerce City, CO; and Santa Monica, CA. By the end of 1997, at least 418 schools made condoms available to students.(24) Although making condoms available in schools remains very controversial, 65% of the U.S. adult population supports condom availability in schools to prevent the transmission of HIV/AIDS.(25)

Numerous community organizations have also implemented programs. At the forefront of these efforts have been the innumerable county or community AIDS projects that have developed programs for youth. Sometimes these include educational programs in schools, but they also include various types of outreach efforts outside of schools. Sometimes they target some of the highest risk groups, such as street youth. Many family planning clinics have also given greater emphasis to HIV and STDs, have initiated policies of giving away free condoms, and have tried to become more friendly and attractive to males. Unfortunately, not many of these efforts have been studied nationwide.

Impact of Education Programs

Before examining the impact of these programs, two considerations should be made. First, these programs face a daunting challenge. A large number of forces encourage youth to engage in sexual activity, including unprotected sexual activity (eg, changing hormones, emotional and physical needs and desires, desires to be an adult and to take risks, ambivalence about becoming pregnant or producing a pregnancy, peer pressures, norms promoting sexual risk-taking, and the omnipresent inaccurate portrayal of sex in the media). In addition, it is known that significant underlying factors, such as the many manifestations of poverty and family and community disorganization, are related to sexual risk-taking behavior, as is detachment from parents or school and lack of a belief in the future.(26) Thus, it may not be reasonable to expect that relatively short educational programs can overcome all these other factors and have a very dramatic impact upon sexual risk-taking behavior. Second, it should be understood that most kinds of educational instruction are evaluated by assessing the impact of instruction upon knowledge, not upon behavior outside of school. For example, history or civics classes are not evaluated by measuring their impact on voting, law breaking, or better citizenry. In contrast, when researchers evaluate the impact of sex or HIV instruction upon sexual or contraceptive behavior, they use dramatically more challenging criteria: changing sexual or contraceptive behavior. Nevertheless, because of the need to identify programs that reduce sexual risk-taking behavior, these more demanding criteria are used in research studies and in this review. There are more than 60 studies that have used experimental or quasi-experimental designs with sample sizes of at least 100 to examine the behavioral impact of school and community education programs that specifically focus on the reduction of sexual risk-taking behavior among adolescents 18 years old or younger.(26) For statistical reasons, it was difficult, if not impossible, for most of these studies to measure the impact of programs upon actual rates of HIV or other STD infections. However, it was possible to measure the impact upon behaviors that are logically related to HIV and STD infection rates: age of initiation of intercourse, frequency of sexual activity, number of sexual partners, condom use, and contraceptive use.

Abstinence Programs

Abstinence programs focus upon the importance of abstinence from sexual intercourse, typically abstinence until marriage. Either these programs do not discuss condoms or contraception or they briefly discuss the failure of condoms and contraceptives to provide complete protection against STD and pregnancy. Thus, these programs are not well suited for those young adults at highest risk--gay males. To date, there are only three studies of abstinence programs that meet reasonable scientific criteria.(27,28,29) None of these studies found both a consistent and significant impact upon delaying the onset of intercourse; in fact, at least one study provided strong evidence that the program did not delay the onset of intercourse.(27) As two of the three studies had some methodological limitations that could have obscured program impact and because three studies cannot measure the impact of the great diversity of abstinence-only programs, the possibility remains that some abstinence-only programs might delay the onset of intercourse, but which programs in particular might be effective is not known at this time. Additional, rigorous evaluations of abstinence-only programs are currently under way.

Sex and HIV Education Programs

These programs differ from the abstinence-only programs in that they often emphasize abstinence as the safest choice and also encourage the use of condoms and other methods of contraception as ways to protect against STDs or pregnancy. This group includes a wide variety of programs, ranging from sex or AIDS education programs taught in school to programs taught in homeless shelters and detention centers. They reflect the considerable creativity and differing perspectives of these agencies. Studies of these programs strongly support the conclusion that sexuality and HIV education curricula do not increase sexual intercourse, either by reducing the age at first intercourse, increasing the frequency of intercourse, or increasing the number of sexual partners. Of the 28 evaluations of middle school, high school, or community sexuality or HIV education programs that measured the impact of the programs on the initiation of intercourse, nine studies found that their respective programs delayed the initiation of sex, 18 studies found that the programs had no significant impact one way or the other, and only one study found that the program hastened the onset of intercourse. Similarly, of 19 studies that measured the impact of programs upon the frequency of sex, five programs decreased the frequency, 13 had no significant impact, and only one increased the frequency. Finally, of 10 studies that measured impact on number of sexual partners, three programs reduced the number of partners, seven had no impact, and none increased the number of sexual partners. Thus, a multitude of studies clearly demonstrates that these programs that emphasize abstinence but also encourage condom and contraceptive use for sexually active youth do not increase sexual behavior and that some of these programs may actually decrease one or more sexual behaviors.(26) Studies of these programs also suggest that some, but not all, of the programs increased condom use or contraceptive use more generally. Eighteen studies examined program impact upon condom use, and 10 of them found that the programs did increase some measure of condom use, whereas the remaining programs had no significant effect.(26) Similarly, 11 studies examined program impact upon the use of contraception more generally, and four of them found significant positive results, with the remaining studies finding no significant effects.(26) In combination, these results indicate that some sex and HIV education programs can significantly increase condom use, whereas other programs do not.

The Effective Program and Research Task Force of the National Campaign to Prevent Teen Pregnancy has reviewed the evidence for the effectiveness of programs in reducing sexual risk-taking behaviors, and has identified five programs with particularly strong evidence for success in delaying sex or increasing condom use. These five include:(30,31,32-34)

• Becoming a Responsible Teen: An HIV Risk Reduction Intervention for Adolescents

• Making a Difference: An Abstinence Approach to STD, Teen Pregnancy, and HIV/AIDS Prevention

• Making Proud Choices: A Safer Sex Approach to STD, Teen Pregnancy, and HIV/AIDS Prevention

• Reducing the Risk: Building Skills to Prevent Pregnancy, STD, and HIV

• Safer Choices: Preventing HIV, Other STD, and Pregnancy.

When these five curricula and other curricula having significant positive behavioral outcomes are compared with curricula without such positive behavioral results, the effective curricula share 10 characteristics, which may be linked to their success, whereas the ineffective curricula lack one or more of these characteristics.

1. Effective programs focused on reducing one or more sexual behaviors that lead to unintended pregnancy or HIV/STD infection. These programs focused narrowly on a small number of specific behavioral goals, such as delaying the initiation of intercourse or using condoms or other forms of contraception; relatively little time was spent addressing other sexuality issues, such as gender roles, dating, or parenthood. Nearly every activity was directed toward the behavioral goals.

2. Effective programs were based on theoretical approaches that have been demonstrated to be effective in influencing other health-related risky behaviors. Such approaches include social cognitive theory,(35) social influence theory,(36) social inoculation theory,(37) cognitive behavioral theory,(38,35) theory of reasoned action,(39) and theory of planned behavior.(21) These theories recognize the fact that the beliefs and values of youth are influenced directly through education by parents, schools, and others, and indirectly through observing the behavior of others and the consequences that befall them. In addition, social influence theories address societal pressures on youth and the importance of helping young people understand those pressures and resist the negative ones. Thus, these programs strive to go far beyond the cognitive level; they focus on recognizing social influences, changing individual values, changing group norms and perceptions of those norms, and building social skills.

   These theories help to specify which particular antecedents the interventions should strive to change (eg, the beliefs, attitudes, norms, confidence, and skills related to sexual behavior) to bring about voluntary change in sexual or contraceptive behavior. Thus, each activity was designed to change one or more antecedents specified by the particular theoretical model for the curriculum, and each important antecedent in the theoretical model was addressed by one or more activities. Although all of the effective curricula focused on antecedents specified by their adopted theories, some program developers actually surveyed students and empirically determined which possible antecedents best predicted desired behavior. Activities in their programs then focused on those particular antecedents.

3. Effective programs gave a clear message about sexual activity and condom or contraceptive use and continually reinforced that message. This particular characteristic appeared to be one of the most important criteria that distinguished effective from ineffective curricula. The effective programs did not simply lay out the pros and cons of different sexual choices and implicitly let the students decide which was right for them; rather, most of the curriculum activities were directed toward convincing the students that abstaining from sex, using condoms consistently, or using other forms of contraception consistently was the right choice, and that unprotected sex was clearly an undesirable choice. To the extent possible, they tried to use group activities to change group norms about what was the expected behavior.

4. Effective programs provided basic, accurate information about the risks of teen sexual activity and about methods of avoiding intercourse or using protection against pregnancy and STDs. Effective programs provided basic information that students needed to assess risks and avoid unprotected sex. Typically, this information was not detailed or comprehensive. For example, the curricula did not provide detailed information about all methods of contraception or different types of STDs. Instead, they provided a foundation: they emphasized the basic facts needed to persuade young people to avoid unprotected sex, and they provided information that would lead to changes in beliefs, attitudes, and perceptions of peer norms. Some curricula also provided more detailed information about how to use condoms correctly.

5. Effective programs included activities that address social pressures that influence sexual behavior. These activities took a variety of forms. For example, several curricula discussed situations that might lead to sex. Most of the curricula discussed "lines" that are typically used to get someone to have sex, and some discussed how to overcome social barriers to using condoms (eg, embarrassment about buying condoms). Some of them also addressed peer norms about having sex or using condoms. For example, some curricula provided data showing that many young people do not have sex or do use condoms, or they had students engage in anonymous decision-making or voting activities in which the tallied decisions or votes demonstrate that students believe they should abstain from sex or use always use condoms.

6. Effective programs provided modeling of, and practice with, communication, negotiation, and refusal skills. Typically, the programs provided information about skills, demonstrated the effective use of those skills, and then provided some type of skill rehearsal and practice (eg, verbal role-playing and written practice). Some curricula taught different ways to say "No" to sex or unprotected sex, how to insist on the use of condoms or other methods of contraception, how to use body language that reinforced the verbal message, how to repeatedly refuse sex or insist on condom use, how to suggest alternative activities, and how to help build the relationship while refusing unprotected sex or refusing to have sex at all. Although all effective curricula gave some attention to skills, there were significant variations in the quality of activities designed to teach skills and also in the time devoted to practicing the skills.

7. Effective programs employed a variety of teaching methods designed to involve the participants and encourage them to personalize the information. Instructors reached students by engaging them in the learning process, not through didactic instruction. Students were involved in numerous experiential classroom and homework activities, such as small group discussions, games or simulations, brainstorming, role-playing, written exercises, verbal feedback and coaching, interviewing parents, locating contraception in local drugstores, and visiting or telephoning family planning clinics. All of these activities improved student involvement in the program, promoted active awareness of the issues, and helped students integrate the information into the context of their own lives.

8. Effective programs incorporated behavioral goals, teaching methods, and materials that were appropriate to the age, sexual experience, and culture of the students. For example, programs for younger adolescents in junior high school, few of whom had engaged in intercourse, focused on delaying the onset of intercourse. Programs designed for high school students, some of whom had engaged in intercourse and some of whom had not, emphasized that students should avoid unprotected intercourse; that abstinence was the best method of avoiding unprotected sex; and that, if students did have sex, condoms should always be used. Some of the curricula were designed for specific racial or ethnic groups and emphasized statistics, values, and approaches tailored to those groups.

9. Effective programs lasted a sufficient length of time to complete important activities. In general, it requires considerable time and multiple activities to change the most important antecedents of sexual risk-taking and to thereby have a real influence on behavior. Thus, short programs (those lasting only a few hours or less) did not appear to be effective, whereas longer programs that had many activities had a greater effect. More specifically, effective programs tended to fall into two categories: those that lasted 14 or more hours, and those that lasted a smaller number of hours but recruited youth who voluntarily participated and worked in small group settings with a leader for each group. (When youth volunteer to participate, they may be more open to instruction than if they are required to sit in a school class. And when they work in small groups, instructors may be able to involve the students more completely, to tailor the material to each group, and to cover more material and more concerns more quickly.)

10. Effective programs selected and provided training for teachers or peer leaders who believed in the program they were implementing. Given the challenges of implementing programs, the effective programs carefully selected teachers and provided them with training. The training, ranging from approximately 6 hours to 3 days in length, addressed the challenge of implementing programs that focus on a sensitive topic and incorporate a variety of interactive activities. In general, the training was designed to give teachers and peer leaders both information on the program and practice using the teaching strategies included in the curricula (eg, conducting role-playing exercises and leading group discussions).

In addition to these 10 characteristics, it has been observed that one or more of these programs have been effective with all racial/ethnic groups and with both males and females. Furthermore, they appear to be particularly effective with those youth who most frequently engage in unprotected sex and therefore at greatest risk of HIV and STD more generally.(40)

When schools make condoms available to students, the number of condoms obtained per student varies greatly from program to program.(41) In general, smaller alternative schools (probably with more high-risk students) distributed many more condoms per student than did larger schools or mainstream schools. In addition, when schools made multiple brands of condoms available in baskets in convenient and private locations and without any restrictions, students obtained many more condoms than when distribution was restricted (eg, when students could only obtain a small number of condoms from school personnel at specified times after brief counseling). Finally, students obtained many more condoms in schools that had health clinics.

To date, only four studies meeting reasonable scientific criteria (eg, experimental or quasi-experimental designs, sample sizes of at least 100, and measurement of behavior) have presented results on the behavioral effects of condom-availability programs in schools.(42-45) All four revealed that making condoms available to students did not increase any measure of sexual behavior. In fact, in two studies, condom availability was associated with reduced sexual activity.

The findings regarding impact on condom use were mixed. The study with the strongest evaluation design assessed the effects of making condoms available through vending machines in five Seattle schools without school-based clinics and through vending machines and baskets in five additional Seattle schools with pre-existing school-based clinics.(44) In neither group of schools was there an increase in condom use. In fact, in the schools with clinics and baskets of condoms, there was, surprisingly, a significant decrease in condom use and a significant increase in oral contraceptive use, suggesting that the clinics may have begun encouraging oral contraceptive use in addition to providing condoms.

A second study measured the impact of making condoms available in baskets in nine Philadelphia schools.(45) Although there were no significant effects upon condom use, relatively small samples may have limited the ability to detect programmatically meaningful results.

The last two studies evaluated the impact of AIDS prevention programs that included both instruction and condom availability in New York City high schools and in Massachusetts.(42,43) Both studies found increases in condom use, but both studies had important methodological limitations (eg, lack of baseline data).

What conclusions can be reached from these four studies about the impact of school condom availability on condom use? There are three logical possibilities. First, the differences in results could be caused by differences in the research methods. If this is true, then this group of studies provides weak overall evidence that school condom availability increases condom use because the strongest study found a negative effect, the second study found a nonsignificant trend in the desired direction, and the third and fourth studies found significant positive effects on condom use. Second, the differences in results could be caused by differences in the communities and in student needs. If young people already have ample access to condoms in their communities, as focus group data suggest they did in Seattle, then making condoms available in schools may not increase condom use. By contrast, if communities do not provide condoms in convenient and confidential or private locations, then making them available in schools may increase student access to condoms and subsequently increase use of condoms. Third, the differences in study results could be due, in part, to the addition of other programmatic components (eg, educational components and the availability of small group discussions or one-on-one counseling) in three of the studies. This explanation is consistent with the studies showing that some sex- and HIV- education programs and some brief counseling interventions increase condom use.

Medical personnel have also implemented prevention programs in their clinics in an effort to reduce unprotected intercourse in adolescents. Thus far, three studies have measured the impact of these one-on-one education or counseling programs on condom use.(46-48) They varied considerably.

In the briefest of the three interventions, African-American male teens attending an STD clinic received either a 14-minute video, or a one-on-one session with a health educator, or standard care.(J) All male teens received the results of their STD tests and appropriate treatment. The experimental design was a rather strong one, but the interventions were very modest, and the study failed to find any significant differences among the behavioral effects of these three treatment models. Notably, condom use increased among all three groups over the six-month time period.

The second study evaluated a relatively modest intervention for female patients with chlamydia.(47) A nurse spent about 10 to 20 minutes discussing chlamydia with the aid of a pamphlet, demonstrated how to put a condom on a banana (and got the patient to practice), and engaged the patient in a brief role-play involving a woman getting her partner to use a condom. An experimental design was used to measure the impact at 6 months and found that those youth who received the special instruction were substantially more likely to use condoms than those youth who received the standard intervention.

The third program focused on HIV/STD prevention and served equal percentages of male and female patients.(48) It included a 15-minute audiotaped risk assessment and education program, a discussion ice-breaker, two brochures on skills and ways to avoid unprotected sex, a brochure on community resources, and parent brochures. On a one-to-one basis, the physician then reviewed the risk assessment with the patient and discussed concerns and methods of avoiding unprotected sex. Results based on an experimental design indicated that the program increased use of condoms for at least three months after the intervention, but the impact dissipated by nine months.

The fact that two of these studies found positive effects on behavior with such brief, modest interventions is encouraging. It should be noted that other studies have found that certain brief clinic interventions can increase contraceptive use. In general, the interventions that increased either condom or contraceptive use focused on sexual, condom, and contraceptive behavior, gave clear messages about appropriate sexual and contraceptive behavior, and included one-on-one consultation about the client's own behavior. Some of them also provided practice in how to insist on using a condom and/or how to actually use a condom. Notably, these relatively brief interventions incorporated some of the 10 characteristics of effective sex and HIV education programs.

At the very least, these studies suggest that clinic-based interventions should be further developed and rigorously evaluated. These results should also encourage medical providers to review their instructional protocols with youth and to spend more time talking with individual adolescent patients about their sexual, condom, and contraceptive activity.

Recognizing the complexity of the problem of teen unprotected sex, STDs, and pregnancy, more multi-component efforts have been implemented to change the communities in which teens live--in the hope that healthier environments might reduce rates of unprotected sex. These initiatives often combine such interventions as media campaigns, increased access to condoms, sex/HIV education classes for teens, and training in parent/child communication.

The evidence on these initiatives is mixed. Each of the studies measured effects on teens throughout the community, not just on those teens directly served by programs.

The first effective intervention included a large, comprehensive social marketing campaign in Portland, Oregon called Project Action.(49) Three public service announcements were aired multiple times on television, condom vending machines were installed in locations recommended by youth, and teenagers were trained to facilitate small-group workshops that focused on decision-making and assertiveness skills. Results indicated that the campaign did not increase the proportion of higher-risk youth who had ever had intercourse, nor did it increase their acquisition of condoms or their use of condoms with their main partners. However, after the campaign began, there was a significant increase in their use of condoms with casual sexual partners; after the campaign ended, this use returned to baseline levels.

The second program with positive effects was similar to Project Action.(50) The Teens Stopping AIDS program in Sacramento included 2,000 30-second public service radio announcements, posters and small promotional materials, skills-building workshops to about 900 youth, peer outreach and a telephone information line. Analyses of multiple cross-sectional telephone surveys indicated that the proportion of youth exposed to the program increased over time, and the amount of exposure to the components was related to condom use at last sex with main partner, as well as to some of the theoretical determinants of such use.

Less encouraging are the results from three studies of similar programs in Seattle and Boston. When Project Action was implemented a second time in Seattle, it significantly increased condom use during the first few months of the program, but not during later months(51) and when similar campaigns were implemented in different parts of Seattle(52) and Boston,(53) they also failed to significantly increase condom use.

In combination, these studies consistently demonstrate that comprehensive community programs do not increase sexual behavior, even when they focus primarily on condom use. In addition, the community-wide initiatives that relied strongly on media, provided skill building education to limited numbers of youth, and either provided a telephone hot line or increased the number of condom vending machines had significant community-wide effects in some studies, but not others, and in those studies with positive effects, the improvement was only for the short term. These results suggest that to be effective for lengthy periods of time, community-wide initiatives need to be intensive and must be sustained.

Many parents and adolescents have observed a paucity of communication between parents and their own teenagers about sexuality. Consequently, programs have been developed to increase this communication and thereby to decrease adolescent sexual risk-taking behavior. Because these programs encourage discussion of sexuality between adolescents and their own parents, they avoid controversy that sometimes thwarts the implementation of other effective programs.

Studies of these programs have produced three general conclusions. First, both the reviewed studies as well as informal discussions with educators who have implemented programs indicate that it is difficult to involve parents in programs that take place outside of their homes.(54) Most parents are unwilling or unable to participate in special programs, even one-night events, especially if they have to travel to a special meeting or gathering. Mothers are more likely to attend than fathers, who are less likely to communicate about sexuality with their children than are mothers.

One approach that did succeed in involving large numbers of parents comprised school classes that used homework assignments in which students were asked to talk with their parents about sexual topics. As a result of these assignments, students commonly did talk with their parents about sexuality, in part because the assignments were a required part of school work, and in part because the parents could talk with their children at home.

Second, although many of the programs showed evidence of increased parent-child communication about sexuality, this increase was typically observed only in the short term and did not endure.(54) Programs with the strongest evidence of increasing parent-child communication were the multisession programs for parents and their children together and the school sexuality education classes with homework assignments to talk with parents.

Third, six studies measured the impact of parent-child communication programs on the initiation of sexual intercourse or condom or contraceptive use, and none of the programs produced any positive significant effects upon any sexual or contraceptive behavior.(54) These results are not encouraging. On the other hand, in different studies, various methodological limitations may have obscured some positive program impact. Furthermore, most of the interventions were not based upon theory, addressed few of the risk and protective factors associated with adolescent sexual risk-taking, and were very modest. Thus, more theory-based and more intensive parent programs might be more effective. In particular, parent programs may be more effective if they focus on other ways in which parents affect the sexual behavior of their children (eg, through appropriate supervision and modeling responsible sexual behavior).

The findings of more than 60 studies support several conclusions about the impact of these programs to reduce sexual risk-taking among adolescents. First, the overwhelming weight of the evidence demonstrates that sex and AIDS education programs do not cause harm, as some people fear. More specifically, these studies indicated that these prevention programs did not increase any measure of sexual activity. Second, these studies also demonstrate that some, but not all, sex and AIDS education programs can reduce sexual risk taking either by delaying sex, reducing the frequency of sex, decreasing the number of sexual partners, or increasing condom use. These effective programs have a number of identifiable characteristics in common that may serve as guideposts for future interventions. Third, these studies suggest that properly designed clinic interventions can have a positive impact on condom use. In contrast, the results of school condom availability programs, community-wide media programs, and programs for parents are less encouraging.

If any or all of the effective programs are implemented more broadly, they can have a modest impact upon reducing adolescent sexual risk-taking behavior. Some of the most effective programs reduced sexual risk taking by roughly a third over an extended period of time. To the extent that these programs reduce sexual risk-taking behavior, then logically they should also reduce STD and HIV transmission. Clearly, they do not represent a complete solution to the problems associated with unprotected intercourse, but they can be effective components in larger overall strategies to reduce HIV transmission.

Consequently, professionals concerned with adolescents can help reduce HIV transmission among youth by supporting the adoption of programs that hold promise for reducing adolescent unprotected sex--especially those programs identified as effective--and by encouraging the development, evaluation, and replication of programs specifically designed for adolescents who engage in particularly high-risk sexual activities.