Advertisement

Sex and HIV Education Programs: Their Impact on Sexual Behaviors of Young People Throughout the World

      Abstract

      This paper reviews 83 studies that measure the impact of curriculum-based sex and HIV education programs on sexual behavior and mediating factors among youth under 25 years anywhere in the world. Two thirds of the programs significantly improved one or more sexual behaviors. The evidence is strong that programs do not hasten or increase sexual behavior but, instead, some programs delay or decrease sexual behaviors or increase condom or contraceptive use. Effective curricula commonly incorporated 17 characteristics that describe the curricula development; the goals, objectives, and teaching strategies of the curricula themselves; and their implementation. Programs were effective across a wide variety of countries, cultures, and groups of youth. Replications of studies also indicate that programs remain effective when implemented by others in different communities, provided all the activities are implemented as intended in similar settings.

      Keywords

      Despite substantial declines in teen pregnancy in the United States, pregnancy and birth rates are still very high [
      Guttmacher Institute
      ], as are the rates of several sexually transmitted diseases (STDs) [
      • Weinstock H.
      • Berman S.
      • Cates W.
      Sexually transmitted diseases among American youth: Incidence and prevalence estimates.
      ]. In other developed countries, teen pregnancy rates are typically much lower than in the United States, but some STD rates are increasing and becoming serious problems [

      United Nations. Demographic Yearbook, 2002. Available at: http://unstats.un.org/unsd/demographic/products/dyb/dybpub2002.htm.

      ,
      Health Protection Agency
      ]. In many developing countries, as increasing numbers of young people delay marriage until they are older, they have also become more likely to have sex before marriage; thus premarital pregnancy rates and some STD rates are increasing [
      ].
      Throughout the world, many people view sex and HIV/STD education programs as a partial solution to these problems [
      • Ross D.
      • Dick B.
      • Ferguson J.
      ]. Indeed, sex and HIV/STD education programs that are based on a written curriculum and that are implemented among groups of youth in school, clinic, or community settings are a promising type of intervention to reduce adolescent sexual risk behaviors. They are often well-designed to be implemented in schools, where they can potentially reach large numbers of youth, yet they can also be implemented in clinic and community settings where they can also reach other youth, including potentially higher risk youth who have dropped out of school.
      There have been many previous reviews of sex and HIV education programs’ impact on behavior, but they typically have been limited to a particular geographical area such as the United States [
      • Kirby D.
      ,
      • Mullen P.
      • Ramierez G.
      • Strouse D.
      • et al.
      Meta-analysis of the effects of behavioral HIV prevention interventions on the sexual risk behavior of sexually experienced adolescents in controlled studies in the United States.
      ] or sub-Saharan Africa [
      • Gallant M.
      • Maticka-Tyndale E.
      School-based HIV prevention programmes for African youth.
      ], or they are now somewhat dated [
      • Kirby D.
      ,
      ], or they do not analyze in depth the characteristics of effective programs.
      This review attempts to overcome those and other limitations. It includes 83 studies from all countries, both developed and developing; it is more recent; it includes programs for youth up to age 25; it presents results for mediating factors as well as outcome behaviors; and it examines in depth the characteristics of effective programs that changed behavior.
      This paper addresses two questions: What are the effects, if any, of curriculum-based sex and HIV education programs on sexual risk behaviors, STD and pregnancy rates, and mediating factors such as knowledge and attitudes that affect those behaviors? What are the common characteristics of the curriculum-based programs that were effective in changing sexual risk behaviors?

      Methods

      Identification of evaluation studies

      To be included in this review, each study had to meet the following criteria:
      The program had to:
      • Be a curriculum- and group-based sex or HIV education program (as opposed to an intervention involving only spontaneous discussion, only one-on-one interaction, or only broad school, community or media awareness activities).
      • Focus on adolescents or young adults ages 9 to 24 years.
      The research methods had to:
      • Include a reasonably strong experimental or quasi-experimental design with both intervention and comparison groups and both pretest and posttest data collection.
      • Have a sample size of at least 100.
      • Measure program impact upon one or more of the following sexual behaviors: initiation of sex, frequency of sex, or number of sexual partners; use of condoms or contraception more generally; composite measures of sexual risk (e.g., frequency of unprotected sex); pregnancy rates; birth rates; and STD rates.
      • Measure impact on those behaviors that can change quickly (i.e., frequency of sex, number of sexual partners, use of condoms, use of contraception or sexual risk-taking) for at least 3 months, or measure impact on those behaviors or outcomes that change less quickly (i.e., initiation of sex, pregnancy rates, or STD rates) for at least 6 months.
      The study had to be completed or published in 1990 or thereafter. (To be as inclusive as possible, studies did not have to be published in peer-reviewed journals to be included in the review.)
      Studies meeting these criteria were identified in several ways, including: searches of 10 databases (PubMed, PsychInfo, Popline, Sociological Abstracts, Psychological Abstracts, Bireme, Dissertation Abstracts, ERIC, CHID, and Biologic Abstracts), reviews of past issues of 12 journals; contacts with researchers at professional meetings and those in the process of completing studies; a review of reports, training materials, and process evaluation reports; and previous literature searches and reviews from various authors.

      Analysis of study results

      All identified studies meeting these criteria were reviewed and specific information from each study was summarized in a one-page summary that included key data such as characteristics of the sample, the characteristics of the intervention, research methods, and effects on both sexual risk behaviors and mediating factors (e.g., relevant knowledge and attitudes). (All of these one-page summaries are available from the first author upon request.)
      All effects on behaviors or mediating factors were considered significant if: (1) they were statistically significant at the p < .05 level and (2) this significance was based on either the total study population or a large subgroup that was roughly at least one third of the population (e.g., males or females, one of the three major racial/ethnic groups in the U.S., or sexually experienced or inexperienced youth).
      Studies sometimes reported results for multiple measures of each behavior, for different time periods, for different subpopulations, or for various combinations of the above. Thus, some studies reported one or a very small number of positive effects on behavior but also reported a large majority of results that were not significant. To avoid presenting only the positive results and to provide a more balanced overview of the results, the following rules for summarizing results were adopted.
      • Regarding different measures of the same outcome behavior, all measures across all studies were rank-ordered according to their probable impact on prevalence. For example, use of condoms over 12 months was ranked higher than was condom use at first sex. Only the results from the highest ranked measure reported in each study were included in tables.
      • Regarding different time periods, because very short-term effects on behaviors would have had little impact on HIV prevalence, only those results for 3 months or 6 months (depending on the behavior) or longer were included in tables.
      • Regarding different subsamples, the results had to describe a subsample representing roughly one third of the sample or more (e.g., males or females) to be included.
      Even these rules for summarizing results provided a more positive picture than all of the results from all studies.
      However, this positive bias was at least partly offset by a different negative bias—many results presented in the studies were based on samples with insufficient power. At least half of the studies reviewed lacked statistical power to detect meaningful program effects on behavior. Moreover, the problem of insufficient power was further aggravated by the fact that studies typically had to divide their samples into various subsamples. For example, to measure the impact of the program on sexual initiation, the samples were typically restricted to those who were sexually inexperienced at baseline, and to measure impact on condom or contraceptive use, the samples were commonly restricted to those who were sexually active.

      Identification of characteristics of effective programs

      After analyzing the behavioral effects of the programs evaluated, we used a three-step process to identify the common characteristics of those programs that were effective at changing behavior.
      First, to generate a comprehensive list of potentially important characteristics of programs, we examined reviews of health education and HIV education programs for adults, reviews of sex and HIV education programs for young adults, and individual studies of sex and HIV education programs for youth.
      Second, to identify the common characteristics of curriculum content (as opposed to curriculum development and implementation), from among the 83 studies, we identified and requested 28 curricula that had the strongest evidence for positive behavioral effects; the evidence for the positive effects of the remaining 55 curricula was less strong (e.g., the results were either not significant or the evaluation designs and/or results were less strong. Of these 28 effective curricula, we successfully obtained 19.
      We then coded most activities in these 19 curricula according to the risk and protective factors they addressed. Activities from different curricula addressing the same risk and protective factor were photocopied, placed in a separate binder for each factor, and subsequently reviewed. Finally, we rated each overall curriculum on each of the potentially important characteristics that was either on the list of potentially important characteristics identified in the first step or that emerged from our in-depth review. Those characteristics that were incorporated into more than 80% of the effective curricula became the eight common characteristics of effective curricula content described below.
      Third, to determine more accurately the characteristics of the process for developing and implementing the effective curricula (as opposed to the content of the curricula), we coded the original research articles and reviewed any other materials (e.g., the curricula themselves) that described how the curricula were developed and implemented. These descriptions became the basis for the five characteristics describing the development of the program and the four characteristics describing the implementation of the program (described below).
      Although we coded the curricula and studies as objectively as we could, our results necessarily had to reflect some degree of judgment, in part, because many studies lacked a clear and detailed description of the program development, content, and implementation.

      Results

      The results are divided into four sections: characteristics of the studies reviewed, impact of programs on sexual risk behaviors and pregnancy and STD rates, impact of programs on mediating factors for sexual risk behaviors, and common characteristics of effective programs.

      Characteristics of the studies reviewed

      Eighty-three studies met the inclusion criteria above [
      • Aarons S.
      • Jenkins R.R.
      • Raine T.R.
      • et al.
      Postponing sexual intercourse among urban junior high school students? A randomized controlled evaluation.
      ,
      • Agha S.
      • Van Rossem R.
      Impact of a school-based peer sexual health intervention on normative beliefs, risk perceptions, and sexual behavior of Zambian adolescents.
      ,
      • Antunes M.
      • Stall R.
      • Paiva V.
      • et al.
      Evaluating an AIDS sexual risk reduction program for young adults in public night schools in Sào Paulo, Brazil.
      ,
      • Aten M.
      • Siegel D.
      • Enaharo M.
      • et al.
      Keeping middle school students abstinent: Outcomes of a primary prevention intervention.
      ,
      • Baker S.
      • Rumakom P.
      • Sartsara S.
      • et al.
      ,
      • Baldwin J.
      • Whiteley S.
      • Baldwin J.
      Changing AIDS- and fertility-related behavior: The effectiveness of sexual education.
      ,

      Blake S, Ledsky R, Lohrmann D, et al. Overall and differential impact of an HIV/STD prevention curriculum for adolescents. Submitted for publication.

      ,

      Borawski E, Trapl E, Goodwin M. Teaching HIV Prevention in Schools: Taking Be Proud! Be Responsible! to the Suburbs. Paper presented at: Psychosocial Workshop of the Population Association of America; Philadelphia, PA, March 29–30, 2005.

      ,
      • Borawski E.
      • Trapl E.
      • Lovegreen L.
      • et al.
      Effectiveness of abstinence-only intervention in middle school teens.
      ,
      • Boyer C.
      • Shafer M.
      • Shaffer R.
      • et al.
      Prevention of sexually transmitted diseases and HIV in young military men: Evaluation of a cognitive-behavioral skills-building intervention.
      ,
      • Boyer C.
      • Shafer M.
      • Shaffer R.
      • et al.
      Evaluation of a cognitive-behavioral, group, randomized controlled intervention trial to prevent sexually transmitted infections and unintended pregnancies in young women.
      ,
      • Boyer C.
      • Shafer M.
      • Tschann J.
      Evaluation of a knowledge- and cognitive-behavioral skills-building intervention to prevent STDs and HIV infection in high school students.
      ,
      • Bryan A.
      • Aiken L.
      • West S.
      Increasing condom use: Evaluation of a theory-based intervention to prevent sexually transmitted diseases in young women.
      ,
      • Cabezon C.
      • Vigil P.
      • Rojas I.
      • et al.
      Adolescent pregnancy prevention: An abstinence-centered randomized controlled intervention in a Chilean public high school.
      ,
      • Caron F.
      • Godin G.
      • Otis J.
      • Lambert L.
      Evaluation of a theoretically based AIDS/STD peer education program on postponing sexual intercourse and on condom use among adolescents attending high school.
      ,
      • Coyle K.
      • Basen-Enquist K.
      • Kirby D.
      • et al.
      Safer choices: Reducing teen pregnancy, HIV and STDs.
      ,
      • Coyle K.
      • Basen-Enquist K.
      • Kirby D.
      • et al.
      Short-term impact of Safer Choices: A multi-component school-based HIV, other STD and pregnancy prevention program.
      ,
      • Coyle K.
      • Kirby D.
      • Marin B.
      • et al.
      Draw the Line/Respect the Line: A randomized trial of a middle school intervention to reduce sexual risk behaviors.
      ,
      • DiClemente R.
      • Wingood G.
      • Harrington K.
      • et al.
      Efficacy of an HIV prevention intervention for African-American adolescent girls.
      ,
      • Diez E.
      • Juárez O.
      • Nebot M.
      • et al.
      Effects on attitudes, knowledge, intentions and behaviour of an AIDS prevention programme targeting secondary school adolescents.
      ,
      • Eggleston E.
      • Jackson J.
      • Rountree W.
      • Pan Z.
      Evaluation of a sexuality education program for young adolescents in Jamaica.
      ,
      • Eisen M.
      • Zellman G.
      • McAlister A.
      Evaluating the impact of a theory-based sexuality and contraceptive education program.
      ,
      • Ekstrand M.
      • Siegel D.S.
      • Nido V.
      • et al.
      ,
      • Erulkar A.
      • Ettyang L.
      • Onoka C.
      • et al.
      Behavior change evaluation of a culturally consistent reproductive health program for young Kenyans.
      ,
      • Fawole I.
      • Asuzu M.
      • Oduntan S.
      • Brieger W.
      A school-based AIDS education programme for secondary school students in Nigeria: A review of effectiveness.
      ,
      • Fisher J.
      • Fisher W.
      • Bryan A.
      • Misovich S.
      Information-motivation-behavioral skills model-based HIV risk behavior change intervention for inner-city high school youth.
      ,
      • Gillmore M.
      • Morrison D.
      • Richey C.
      • et al.
      Effects of a skill-based intervention to encourage condom use among high risk heterosexually active adolescents.
      ,
      Girls Incorporated
      ,
      Girls Incorporated
      ,
      • Goertzel T.
      • Bluenond-Langner M.
      What is the impact of a campus AIDS education course?.
      ,
      • Gottsegen E.
      • Philliber W.
      Impact of a male sexuality responsibility program on young males.
      ,
      • Harrington N.
      • Giles S.
      • Hoyle R.
      • et al.
      Evaluation of the All Stars character education and problem behavior prevention program: Effects on mediator and outcome variables for middle school students.
      ,
      • Harvey B.
      • Stuart J.
      • Swan T.
      Evaluation of a drama-in-education programme to increase AIDS awareness in South African high schools: A randomized community intervention trial.
      ,
      • Harvey B.
      • Stuart J.
      • Swan T.
      Statistical methods and the evaluation of school-based AIDS education in Africa.
      ,
      • Howard M.
      Delaying the start of intercourse among adolescents.
      ,
      • Howard M.
      • McCabe J.
      Helping teenagers postpone sexual involvement.
      ,
      • Hubbard B.M.
      • Giese M.L.
      • Rainey J.
      A replication of Reducing the Risk, a theory-based sexuality curriculum for adolescents.
      ,

      Jemmott III J. Effectiveness of an HIV/STD risk-reduction intervention implemented by nongovernmental organizations: A randomized controlled trial among adolescents. American Psychological Association Annual Conference, 2005.

      ,
      • Jemmott III, J.
      • Jemmott L.
      • Braverman P.
      • et al.
      HIV/STD risk reduction interventions for African American and Latino adolescent girls at an adolescent medicine clinic.
      ,
      • Jemmott III, J.
      • Jemmott L.
      • Fong G.
      Reductions in HIV risk-associated sexual behaviors among black male adolescents: Effects of an AIDS prevention intervention.
      ,
      • Jemmott III, J.
      • Jemmott L.
      • Fong G.
      • et al.
      Reducing HIV risk-associated sexual behaviors among African American adolescents: Testing the generality of intervention effects.
      ,
      • Jemmott III, J.
      • Jemmott L.
      • Fong G.
      Abstinence and safer sex: HIV risk-reduction interventions for African-American adolescents: A randomized controlled trial.
      ,
      • Kinsler J.
      • Sneed C.
      • Morisky D.
      • Ang A.
      Evaluation of a school-based intervention for HIV/AIDS prevention among Belizean adolescents.
      ,
      • Kirby D.
      • Barth R.
      • Leland N.
      • Fetro J.
      Reducing the Risk: Impact of a new curriculum on sexual risk-taking.
      ,
      • Kirby D.
      • Baumler E.
      • Coyle K.
      • et al.
      The “Safer Choices” intervention: Its impact on the sexual behaviors of different subgroups of high school students.
      ,
      • Kirby D.
      • Korpi M.
      • Adivi C.
      • Weissman J.
      An impact evaluation of Project SNAPP: An AIDS and pregnancy prevention middle school program.
      ,
      • Kirby D.
      • Korpi M.
      • Barth R.P.
      • et al.
      ,
      • Kirby D.
      • Korpi M.
      • Barth R.P.
      • et al.
      The impact of the Postponing Sexual Involvement curriculum among youths in California.
      ,
      • Klepp K.
      • Ndeki S.
      • Leshabari M.
      • et al.
      AIDS education in Tanzania: Promoting risk reduction among primary school children.
      ,
      • Klepp K.
      • Ndeki S.
      • Seha A.
      • et al.
      AIDS education for primary school children in Tanzania: An evaluation study.
      ,
      • Kvalem I.
      • Sundet J.
      • Rivø K.
      • et al.
      The effect of sex education on adolescents’ use of condoms: Applying the Solomon four-group design.
      ,
      • LaChausse R.
      Evaluation of the Positive Prevention HIV/STD Curriculum for Students Grades 9–12.
      ,
      • Levy S.R.
      • Perhats C.
      • Weeks K.
      • et al.
      Impact of a school-based AIDS prevention program on risk and protective behavior for newly sexually active students.
      ,
      • Li X.
      • Stanton B.
      • Freigelman S.
      • Galbraith J.
      Unprotected sex among African American adolescents: A three-year study.
      ,
      • Lieberman L.D.
      • Gray H.
      • Wier M.
      • et al.
      Long-term outcomes of an abstinence-based, small-group pregnancy prevention program in New York City schools.
      ,
      • Little C.B.
      • Rankin A.
      An evaluation of the Postponing Sexual Involvement curriculum among upstate New York eighth graders.
      ,
      • Magura S.
      • Kang S.
      • Shapiro J.L.
      Outcomes of intensive AIDS education for male adolescent drug users in jail.
      ,
      • Main D.S.
      • Iverson D.C.
      • McGloin J.
      • et al.
      Preventing HIV infection among adolescents: Evaluation of a school-based education program.
      ,
      • Martinez-Donate A.
      • Melbourne F.
      • Zellner J.
      • et al.
      Evaluation of two school-based HIV prevention interventions in the border city of Tijuana, Mexico.
      ,
      • Maticka-Tyndale E.
      • Brouillard-Coyle C.
      • Gallant M.
      • et al.
      ,
      • McCauley A.
      • Pick S.
      • Givaudan M.
      ,
      • Mellanby A.
      • Phelps F.
      • Crichton N.
      • Tripp J.
      School sex education: An experimental programme with educational and medical benefit.
      ,
      • Mitchel-DiCenso A.
      • Thomas B.H.
      • Devlin M.C.
      • et al.
      Evaluation of an educational program to prevent adolescent pregnancy.
      ,
      • Moberg D.P.
      • Piper D.L.
      An outcome evaluation of Project Model Health: A middle school health promotion program.
      ,
      • Moberg D.P.
      • Piper D.L.
      The Healthy for Life Project: Sexual risk behavior outcomes.
      ,
      • Murray N.
      • Toledo V.
      • Luengo X.
      • et al.
      ,
      • Nicholson H.
      • Postrado L.
      ,
      • Nicholson H.J.
      • Postrado L.T.
      ,
      • Nicholson H.J.
      • Postrado L.T.
      ,
      • Postrado L.T.
      • Nicholson H.J.
      Effectiveness in delaying the initiation of sexual intercourse of girls aged 12–14: Two components of the Girls Incorporated Preventing Adolescent Pregnancy Program.
      ,
      • Reddy P.
      • James S.
      • McCauley A.
      ,
      • Ross D.
      ,
      • Rotheram-Borus M.
      • Gwadz M.
      • Fernandez M.
      • Srinivasan S.
      Timing of HIV interventions on reductions in sexual risk among adolescents.
      ,
      • Rotheram-Borus M.
      • Lee M.
      • Murphy D.
      • et al.
      Efficacy of a prevention intervention for youths living with HIV.
      ,
      • Rotheram-Borus M.
      • Murphy D.
      • Fernandez M.
      • Srinivasan S.
      • et al.
      A brief HIV intervention for adolescents and young adults.
      ,
      • Rotheram-Borus M.
      • Song J.
      • Gwadz M.
      • et al.
      Reductions in HIV risk among runaway youth.
      ,
      • Rotheram-Borus M.J.
      • Koopman C.
      • Haigners C.
      • Davies M.
      Reducing HIV sexual risk behaviors among runaway adolescents.
      ,
      • Schaalma H.
      • Kok G.
      • Bosker R.
      • et al.
      Planned development and evaluation of AIDS/STD education for secondary school students in the Netherlands: Short-term effects.
      ,
      • Seidman M.
      • Vigil P.
      • Klaus H.
      • et al.
      ,
      • Siegel D.
      • Aten M.
      • Enaharo M.
      Long-term effects of a middle school- and high school-based human immunodeficiency virus sexual risk prevention intervention.
      ,
      • Siegel D.
      • DiClemente R.
      • Durbin M.
      • et al.
      Change in junior high school students’ AIDS-related knowledge, misconceptions, attitudes, and HIV-prevention behaviors: Effects of a school-based intervention.
      ,
      • Slonim-Nevo V.
      • Auslander W.F.
      • Ozawa M.N.
      • Jung K.G.
      The long-term impact of AIDS-preventive interventions for delinquent and abused adolescents.
      ,
      • Smith P.
      • Weinman M.
      • Parrilli J.
      The role of condom motivation education in the reduction of new and reinfection rates of sexually transmitted diseases among inner-city female adolescents.
      ,
      • St. Lawrence J.
      • Crosby R.
      • Brasfield T.
      • O’Bannon III, R.
      Reducing STD and HIV risk behavior of substance-dependent adolescents: A randomized controlled trial.
      ,
      • St. Lawrence J.S.
      • Jefferson K.W.
      • Alleyne E.
      • et al.
      Cognitive-behavioral intervention to reduce African American adolescents’ risk for HIV infection.
      ,
      • St. Pierre T.L.
      • Mark M.M.
      • Kaltreider D.L.
      • Aikin K.J.
      A 27-month evaluation of a sexual activity prevention program in Boys & Girls Clubs across the nation.
      ,
      • Stanton B.
      • Guo J.
      • Cottrell L.
      • et al.
      The complex business of adapting effective interventions to new populations: An urban to rural transfer.
      ,
      • Stanton B.
      • Li X.
      • Galbraith J.
      • et al.
      Sexually transmitted diseases, human immunodeficiency virus and pregnancy prevention.
      ,
      • Stanton B.
      • Li X.
      • Kahihuata J.
      • et al.
      Increased protected sex and abstinence among Namibian youth following a HIV risk-reduction intervention: A randomized, longitudinal study.
      ,
      • Stanton B.
      • Li X.
      • Ricardo I.
      • et al.
      A randomized, controlled effectiveness trial of an AIDS prevention program for low-income African-American youths.
      ,
      • Stephenson J.
      • Strange V.
      • Forrest S.
      • et al.
      Pupil-led sex education in England (RIPPLE study): Cluster-randomised intervention trial.
      ,

      Thomas B, Mitchell A, Devlin M, et al, (eds.). Small group sex education at school: The McMaster Teen Program. In: Miller BC, Card JJ, Paikoff RL, Peterson JL, (eds). Preventing Adolescent Pregnancy. Newbury Park, CA: Sage, 1992.

      ,
      • Turner J.
      • Korpita E.
      • Mohn L.
      • Hill W.
      Reduction in sexual risk behaviors among college students following a comprehensive health education intervention.
      ,
      • Villarruel A.
      • Jemmott III, J.
      • Jemmott L.
      A randomized controlled trial testing an HIV prevention intervention for Latino youth.
      ,
      • Walter H.J.
      • Vaughn R.D.
      AIDS risk reduction among a multiethnic sample of urban high school students.
      ,
      • Warren W.K.
      • King A.J.C.
      ,
      • Weed S.E.
      • Olsen J.A.
      • DeGaston J.
      • Prigmore J.
      ,
      • Weeks K.
      • Levy S.R.
      • Gordon A.K.
      • et al.
      Does parental involvement make a difference? The impact of parent interactive activities on students in a school-based AIDS prevention program.
      ,
      • Wenger N.
      • Greenberg J.
      • Hilbourne L.
      • et al.
      Effect of HIV antibody testing and AIDS education on communication about HIV risk and sexual behavior: A randomized, controlled trial in college students.
      ,
      • Wight D.
      • Raab G.
      • Henderson M.
      • et al.
      The limits of teacher-delivered sex education: Interim behavioral outcomes from a randomised trial.
      ,

      Zimmerman R, Cupp P, Hansen G, et al. The effects of a school-based HIV and pregnancy prevention program in rural Kentucky. J School Health. In press.

      ,

      Zimmerman R, Donohew L, Sionéan C, et al. Effects of a school-based, theory driven HIV and pregnancy prevention curriculum. Perspect Sex Reprod Health. In press.

      ]. Of these, 56 were conducted in the United States; 9 in other developed countries (Canada, Netherlands, Norway, Spain, and the United Kingdom); and the remaining 18 in developing countries (Belize, Brazil, Chile, Jamaica, Kenya, Mexico, Namibia, Nigeria, South Africa, Tanzania, Thailand, and Zambia).
      Despite the fact that these programs were implemented throughout the world, they had numerous characteristics in common and many of them incorporated many of the characteristics of programs previously found to be associated with effectiveness [
      • Kirby D.
      ].
      For example, 52% focused on preventing only STD/HIV, 31% focused on preventing both STD/HIV and pregnancy, and 17% focused only on teen pregnancy. This greater emphasis on STD/HIV undoubtedly reflects the worldwide concern about young adults contracting HIV and the funds and other resources devoted to reducing STD/HIV transmission.
      Virtually all the programs encouraged specific sexual and protective behaviors. The vast majority of the programs encouraged abstinence, but also discussed or promoted the use of condoms and/or other forms of contraception if young people chose to be sexually active. Only 7% of the programs were abstinence-only programs. All of these were in the United States. Only a few focused only on condoms. Typically, these were designed for older youth who were already likely to be sexually active.
      More than four fifths of the programs (83%) identified one or more theories that formed the basis for their programs, and often specified particular psychosocial mediating factors to be changed. Social learning theory and its sequel, social cognitive theory, formed the basis for more than half (54%) of the interventions. Related theories identifying some of the same mediating factors were mentioned by substantial percentages of other studies: theory of reasoned action (19%); health belief model (12%); theory of planned behavior (10%); and the information, motivation, and behavioral skills model (10%).
      Nearly all (90%) of the interventions included at least two different interactive activities designed to involve youth and help them personalize the information (e.g., role playing, simulations or individual worksheets that applied lessons to their lives).
      Finally, at least 90% of the programs trained their educators before the educators implemented curriculum activities. Some of the remaining 10% of programs may also have trained their educators, but their respective reports or articles did not mention the training.
      It should be noted parenthetically that some of these commonalities reflected the criteria for inclusion in this review. Only studies that addressed STD/HIV or pregnancy and were both curriculum-based and group-based were included; broad youth development programs or sex education programs that did not address STD/HIV or pregnancy at all were not included.
      The one area of great variation in these programs involved length of study. While the mean length was 12 hours, the actual lengths ranged from less than one hour to 48 hours. About two-thirds had between 2 and 15 sessions, but 11% included only 1 session, and 22% had 16 or more sessions.
      To evaluate program impact, half (51%) of these studies employed an experimental design with random assignment of individual youth, classrooms of youth, or entire schools or communities, while the remaining half used a quasi-experimental design. To be included in this review, all quasi-experimental designs had to have both intervention and comparison groups and both pretest and post-test data. About 88% of all the studies used a matched-cohort design in which they linked baseline and follow-up survey data, while the others (only 12%) used unmatched pre and post cross-sectional surveys.
      All measures of sexual and contraceptive behavior relied on self-reports. Although some under- and over-reporting of these behaviors undoubtedly occurred, these data are generally believed to be reasonably reliable and valid in developed countries, and often, but not always, the biases may be similar in both the intervention and control groups, especially when the data are collected confidentially by data collectors months after the end of the intervention [
      • Sonenstein F.
      ]. However, this may not be the case in some developing countries, where youth are far less accustomed to talking about sexual behavior or completing questionnaires about personal behavior [
      • Plummer M.
      • Ross D.
      • Wight D.
      • et al.
      “A bit more truthful”: The validity of adolescent sexual behaviour data collected in rural northern Tanzania using five methods.
      ].
      Measures of pregnancy and STD can be measured with laboratory tests and thereby overcome many of the problems of self-reported data. Of the 13 studies that measured impact on pregnancy, 4 used pregnancy tests; of the 10 studies that measured impact on STD, 5 used a laboratory test. The rest relied on self-reports.
      As noted above, to be included in this review, studies also had to measure behavior for at least 3 months (or initiation of sex for at least 6 months). Just over half (59%) of the studies measured impact for a year or longer, while 22% measured impact for 2 years or longer. The longest study measured impact over 57 months.
      In sum, as the field is maturing, increasingly large percentages of studies have used experimental designs, have used cohort designs, and have measured long-term impact on behavior. These changes as well as improvements in other areas (e.g., more rigorous and sophisticated statistical analyses) demonstrate that standards are becoming more rigorous. On the other hand, many of these studies had significant limitations such as limited explanations of the programs, problems with implementation, weak evaluation designs, measurement issues, and statistical shortcomings.

      Impact of programs on sexual risk behaviors and pregnancy and STD rates

      All but one of the 83 studies measured program impact on one or more of six sexual behaviors: initiation of sex, frequency of sex, number of sexual partners, condom use, contraceptive use in general, and composite measures of sexual risk-taking. A few studies reported on pregnancy and STD rates (Table 1).
      Table 1Number of studies reporting effects on different sexual behaviors and outcomes
      None of the studies measured all of the outcomes. Thus, the sum of the number of negative, nonsignificant and positive results for each outcome is less than the total number of studies.
      Outcomes measuredU.S. (N = 56)Other developed countries (N = 9)Developing countries (N = 18)All countries (n = 83)
      Delay sex(n = 30)(n = 8)(n = 14)(n = 52)
       Hastened initiation10012%
       No significant results15682956%
       Delayed initiation14262242%
      Reduce frequency of sex(n = 24)(n = 2)(n = 5)(n = 31)
       Increased frequency210310%
       No significant results15131961%
       Reduced frequency702929%
      Reduce number of partners(n = 26)(n = 0)(n = 8)(n = 34)
       Increased numbers10013%
       No significant results16052162%
       Reduced number9031235%
      Increase condom use(n = 37)(n = 5)(n = 12)(n = 54)
       Reduced use00000%
       No significant results19452852%
       Increased use18172648%
      Increase contraceptive use(n = 11)(n = 2)(n = 2)(n = 15)
       Reduced use10017%
       No significant results512853%
       Increased use510640%
      Reduce sexual risk taking(n = 25)(n = 1)(n = 2)(n = 28)
       Increased risk00000%
       No significant results11121450%
       Reduced risk14001450%
      Reduce pregnancy: self-report(n = 6)(n = 3)(n = 0)(n = 9)
       Increased number100111%
       No significant results330667%
       Reduced number200222%
      Reduce pregnancy: laboratory test(n = 2)(n = 0)(n = 2)(n = 4)
       Increased number00000%
       No significant results201375%
       Reduced number001125%
      Reduce STDs: self-report(n = 3)(n = 0)(n = 2)(n = 5)
       Increased number100120%
       No significant results202480%
       Reduced number00000%
      Reduce STDs: laboratory test(n = 4)(n = 0)(n = 1)(n = 5)
       Increased number001120%
       No significant results200240%
       Reduced number200240%
      a None of the studies measured all of the outcomes. Thus, the sum of the number of negative, nonsignificant and positive results for each outcome is less than the total number of studies.

      Initiation of sex

      An important measure of sexual activity is timing of initiation of sex. The studies reviewed demonstrate that these programs in general did not hasten the initiation of sex, and some delayed the initiation of sex. Of the 52 studies that measured impact on this behavior, 22 (42%) found that the programs significantly delayed the initiation of sex among one or more groups for at least 6 months, 29 (55%) found no significant impact, and 1 found the program hastened the initiation of sex.

      Frequency of sex

      A second measure of sexual activity is the frequency of sex during a specified period of time (e.g., 3 or 6 months prior to the survey). This measure includes whether or not respondents had sex at all during that period of time. Of the 31 studies that measured impact on frequency, 9 (29%) reduced the frequency, 19 (61%) found no significant change in frequency, and 3 (all in developed countries) found increased frequency among any major groups at any point in time.

      Number of sexual partners

      A third common measure of sexual activity is number of sexual partners during a specified period of time prior to the survey. This measure is especially important for STD transmission. Of 34 studies measuring this factor, 12 (35%) found a decrease in the number of sexual partners, while 21 (62%) found no significant impact, and 1 (3%) found a negative impact.

      Condom use

      Of the 54 studies measuring program impact on condom use, almost half (48%) showed increased condom use; none found decreased condom use.

      Contraceptive use in general

      Of the 15 studies measuring impact, 6 showed increased contraceptive use, 8 showed no impact, and 1 showed decreased contraceptive use.

      Sexual risk-taking

      Some studies (28) developed composite measures of sexual activity and condom use (e.g., frequency of sex without condoms or number of unprotected sexual partners). Half of them found that the programs significantly reduced sexual risk-taking. None of them found increased sexual risk-taking.

      Pregnancy rates

      Of the 13 studies that measured pregnancy rates, 3 found significant positive impacts, 9 found insignificant impacts, and 1 found a significant negative impact.

      STD rates

      Of the 10 studies that measured impact on STD rates, 2 found positive impacts, 6 found no significant impact, and 2 found negative impacts.
      Overall, these studies strongly indicate that these programs were far more likely to have a positive impact on behavior than a negative impact. Across all 83 studies, two thirds (65%) had a significant positive impact on one or more of these sexual behaviors or outcomes, while only 7% had a significant negative impact on one or more of these behaviors or outcomes. Given the large number of tests of significance across all of these studies, some, but not all, of the positive and negative results undoubtedly occurred by chance. Given the large proportion of studies that found significant positive results, a few, but not all, probably occurred by chance. On the other hand, given that multiple coefficients were examined in each study, the percentage of significant negative results that was found is roughly equal to or less than the number that is likely to have occurred by chance.
      One third (33%) of the programs had a positive impact on two or more behaviors or outcomes. For example, in the U.S., Becoming a Responsible Teen increased abstinence, reduced the number of sexual partners, increased condom use, and reduced unprotected sex [
      • St. Lawrence J.
      • Crosby R.
      • Brasfield T.
      • O’Bannon III, R.
      Reducing STD and HIV risk behavior of substance-dependent adolescents: A randomized controlled trial.
      ]. Also in the U.S., the Safer Choices intervention delayed the initiation of sex among Hispanic youth, and increased both condom and contraceptive use among both boys and girls of all races/ethnicities [
      • Kirby D.
      • Baumler E.
      • Coyle K.
      • et al.
      The “Safer Choices” intervention: Its impact on the sexual behaviors of different subgroups of high school students.
      ]. In Tanzania, the MEMA kwa Vijana intervention both reduced the number of sexual partners among boys and increased condom use among both boys and girls [
      • Ross D.
      ]. These effects in these three studies are particularly noteworthy, because all three studies employed experimental designs and measured impact on behavior for at least 1 year. More generally, studies indicate that it is possible both to reduce sexual behavior and to increase condom or contraceptive use with the same program.
      While the positive effects of some curriculum-based programs lasted only a few months, the effects of other programs lasted for years. For example, the MEMA kwa Vijana [
      • Ross D.
      ] intervention found positive behavioral effects over a 36-month period and Safer Choices [
      • Coyle K.
      • Basen-Enquist K.
      • Kirby D.
      • et al.
      Safer choices: Reducing teen pregnancy, HIV and STDs.
      ] found positive behavioral effects over a 31-month period.
      These findings were remarkably robust. The patterns of findings remained the same regardless of the type of experimental design used. Whereas 63% of the 41 studies with a quasi-experimental design had a significant positive impact on one or more behaviors, 66% of the 42 studies with an experimental design had a positive impact on one or more behaviors.
      The patterns of findings were also similar in both developed and developing countries. Programs were effective with both low- and middle-income youth, in both rural and urban areas, with girls and boys, with different age groups, and in school, clinic, and community settings (results not shown). (This does not mean that the same program was effective with all of these groups in all of these areas, but simply that different programs were effective with all of these groups in all of these areas.)
      And finally, while there were only six studies that focused only on abstinence (all in the U.S.), there were a few positive results (and one negative result) for these programs, just as there were many positive results and a few scattered negatives results for the far more numerous programs that commonly emphasized both abstinence and condom or contraceptive use.

      Replication of studies

      A critically important question is whether or not a program that has been found to be effective when designed, implemented, and evaluated by a well-funded and highly skilled research team, will subsequently be effective when implemented by others in other communities. Four interventions in the United States have now been evaluated between two and five times [

      Borawski E, Trapl E, Goodwin M. Teaching HIV Prevention in Schools: Taking Be Proud! Be Responsible! to the Suburbs. Paper presented at: Psychosocial Workshop of the Population Association of America; Philadelphia, PA, March 29–30, 2005.

      ,
      • Hubbard B.M.
      • Giese M.L.
      • Rainey J.
      A replication of Reducing the Risk, a theory-based sexuality curriculum for adolescents.
      ,

      Jemmott III J. Effectiveness of an HIV/STD risk-reduction intervention implemented by nongovernmental organizations: A randomized controlled trial among adolescents. American Psychological Association Annual Conference, 2005.

      ,
      • Jemmott III, J.
      • Jemmott L.
      • Fong G.
      Reductions in HIV risk-associated sexual behaviors among black male adolescents: Effects of an AIDS prevention intervention.
      ,
      • Jemmott III, J.
      • Jemmott L.
      • Fong G.
      • et al.
      Reducing HIV risk-associated sexual behaviors among African American adolescents: Testing the generality of intervention effects.
      ,
      • Jemmott III, J.
      • Jemmott L.
      • Fong G.
      Abstinence and safer sex: HIV risk-reduction interventions for African-American adolescents: A randomized controlled trial.
      ,
      • Kirby D.
      • Barth R.
      • Leland N.
      • Fetro J.
      Reducing the Risk: Impact of a new curriculum on sexual risk-taking.
      ,
      • St. Lawrence J.
      • Crosby R.
      • Brasfield T.
      • O’Bannon III, R.
      Reducing STD and HIV risk behavior of substance-dependent adolescents: A randomized controlled trial.
      ,
      • St. Lawrence J.S.
      • Jefferson K.W.
      • Alleyne E.
      • et al.
      Cognitive-behavioral intervention to reduce African American adolescents’ risk for HIV infection.
      ,
      • Stanton B.
      • Guo J.
      • Cottrell L.
      • et al.
      The complex business of adapting effective interventions to new populations: An urban to rural transfer.
      ,
      • Stanton B.
      • Li X.
      • Galbraith J.
      • et al.
      Sexually transmitted diseases, human immunodeficiency virus and pregnancy prevention.
      ,

      Zimmerman R, Cupp P, Hansen G, et al. The effects of a school-based HIV and pregnancy prevention program in rural Kentucky. J School Health. In press.

      ,

      Zimmerman R, Donohew L, Sionéan C, et al. Effects of a school-based, theory driven HIV and pregnancy prevention curriculum. Perspect Sex Reprod Health. In press.

      ,
      • St. Lawrence J.
      • Crosby R.
      • Belcher L.
      • et al.
      Sexual risk reduction and anger management interventions for incarcerated male adolescents: A randomized controlled trial of two interventions.
      ]. These replications reveal that these curricula consistently had similar positive behavioral effects when they were replicated, provided (1) all activities were implemented as designed and (2) they were implemented in the same type of setting and with similar populations of youth. When many activities were omitted or the setting was changed (e.g., from voluntary Saturday programs to required in-school programs), the curricula were less likely to have a positive effect.

      Impact of programs on mediating factors for sexual risk behaviors

      Although the review of the studies above provides strong evidence that some programs had an impact on sexual risk behaviors, without the results of the mediating factors, it does not specify how or why these programs had an impact. Those questions can be partially answered by examining programmatic impact on the mediating factors that programs attempted to change in order to change behavior. Table 2 provides the results for 71 different mediating factors that were measured by one or more of the 83 studies. Those factors that are lightly shaded meet two criteria and therefore have stronger evidence that programs can modify them: (1) at least three programs significantly improved them and (2) at least half of the studies that measured them found significant improvements.
      Table 2Number of programs having effects on mediating factors that may affect sexual behavior or condom or contraceptive use
      None of the studies measured all of the outcomes. Thus, the sum of the number of negative, nonsignificant and positive results for teach outcome is less than the total number of studies.
      Pos
      Pos = Positive (desirable) effect on factor; NS = Nonsignificant; Neg = Negative (undesirable) effect on factor.
      NSNeg
      Knowledge
       Overall knowledge of sexual issues
      Lightly shaded factors meet two criteria and therefore have stronger evidence that programs can modify them: (1) at least three programs significantly improved them and (2) at least half of the studies that measured them found significant improvements.
      720
       Knowledge of pregnancy500
       Knowledge of STD830
       Knowledge of HIV2830
       Knowledge of abstinence200
       Knowledge of methods of contraception420
       Knowledge of condoms530
       Knowledge of methods to prevent STD/HIV610
       Knowledge of community or reproductive health services110
       Knowledge of one’s own sexual limits120
      Perceived risk
       Perception of pregnancy risk030
       Perception of STD risk110
       Perception of HIV risk880
      Perceived severity of consequences
       Perception of severity of pregnancy and childbearing (including attitude toward childbearing)230
       Perception of severity of STDs100
       Perception of severity of HIV/AIDS310
      Personal values and attitudes
       Values about sex/abstinence14100
       Regret about initiating sex100
       Attitude about pressuring someone to have sex (including right to say no to sex)320
       Attitudes toward condoms1480
       Belief that condoms are a hassle and reduce pleasure230
       Perceived barriers to using condoms430
       Attitude toward risky sexual behavior and AIDS prevention520
       Self-approval to use condoms110
       Attitudes toward HIV+ people (including interacting with them)600
       Homophobia100
      Perceived peer values and behavior
       Perception of peer norms/behavior regarding sex9131
       Perception of peer norms/behavior regarding condoms460
       Perception of peer norms/behavior regarding avoiding risk320
       Influences of peers010
      Perceived partner values
       Perceived partner norms and reaction to condom use030
      Self-efficacy and skills
       Self-efficacy to show love and affection without sex130
       Self-efficacy to discus sex, condoms, or contraception with partner030
       Self-efficacy to refuse sex842
       Self-efficacy to obtain condoms130
       Self-efficacy to use condoms1241
       Condom use skills100
       Self-efficacy to avoid STD/HIV risk and risk behaviors (e.g., to abstain or use condoms)790
       General sexual negotiation skills210
       Social competency/locus of control201
       Self-esteem010
       Self-efficacy to provide information to peers010
      Motivation/Intentions
       Intention to discuss AIDS, STDs, and past partners with new partner100
       Intention to discuss condoms with partner210
       Intention to abstain from sex, or restrict sex or partners1060
       Intention to use a condom1040
       Intention to avoid unprotected sex (including perceived likelihood of having sex)320
      Communication
       Communication with partner re AIDS, STDs, and past partners430
       Communication with boy/girlfriend or partner regarding abstinence or condom use140
       Communication with parents or other adult about sex, condoms, or contraception821
       Comfort talking with parents about sex, condoms, or contraception100
      Other possible mediating behaviors
       Using alcohol or drugs371
       Using alcohol or drugs before sex030
       Having a boyfriend or girlfriend020
       Engaging in coercive behavior010
       Experiencing violence in relationship020
       Avoiding places and situations that could lead to sex (including pre-coital sexual activities)420
       Attending reproductive health clinic010
       Obtaining and carrying a condom320
       Putting a condom on partner (females only)100
       Being tested for STD010
       Being tested for HIV010
      Relationship with parents
       Relationship with parents100
       Parental respect200
       Relevance of parents’ concern about sex100
       Perceived parent concern or values about having sex and using condoms110
      Psychological states
       Self-esteem010
       Depression and mental health010
       Concern about health010
       Future orientation100
       Enjoyment of sex010
      a None of the studies measured all of the outcomes. Thus, the sum of the number of negative, nonsignificant and positive results for teach outcome is less than the total number of studies.
      b Pos = Positive (desirable) effect on factor; NS = Nonsignificant; Neg = Negative (undesirable) effect on factor.
      c Lightly shaded factors meet two criteria and therefore have stronger evidence that programs can modify them: (1) at least three programs significantly improved them and (2) at least half of the studies that measured them found significant improvements.
      Of those programs that measured impact, most increased knowledge about HIV, STDs, and pregnancy (including methods of preventing STD/HIV and pregnancy). Half of the 16 studies that measured impact on perceived HIV risk were effective at increasing this perceived risk. More than 60% of the many studies measuring impact on values and attitudes regarding any sexual topic were effective in improving the measured values and attitudes. About 40% of the 29 studies that measured impact on perceived peer sexual behavior and norms significantly improved these perceptions. More than half of those studies that measured impact on self-efficacy to refuse unwanted sex improved that self-efficacy, and more than two thirds increased self-efficacy to use condoms. Ten of 16 programs increased motivation or intention to abstain from sex or restrict the number of sex partners, and 10 of 14 programs increased intention to use a condom. Eight of 11 programs increased communication with parents or other adults about sex, condoms, or contraception. In contrast, less than 30% of the programs had a positive impact on use of drugs or alcohol, perhaps in part, because reducing use of alcohol or drugs was not the focus of these programs.
      In sum, the evidence was strong that many programs had positive effects on relevant knowledge, awareness of risk, values and attitudes, self-efficacy, and intentions—the very factors specified by many psychosocial theories as being the determinants of behavior. Furthermore, all of these factors have been demonstrated empirically to be related to their respective sexual behaviors [
      • Kirby D.
      • Lepore G.
      • Ryan J.
      ]. Thus, it appears highly likely that changes in these factors contributed to the changes in sexual risk-taking behaviors.

      Characteristics of effective curricula

      The in-depth analyses of effective programs identified 17 characteristics that described these programs and are presented in Figure 1. Three types of evidence suggest that these characteristics may have contributed to the success of these programs. First, a large majority of the effective programs shared most of these characteristics. Second, programs that incorporated these characteristics were more likely to change behavior positively than programs that did not incorporate many of these characteristics. Third, several studies involved a comparison of the impact of skill-based curricula that incorporated all (or nearly all) of these characteristics with the impact of knowledge-based curricula that did not incorporate many of these characteristics. Consistently, the skill-based programs were more effective at changing behavior than were the knowledge-based programs [
      • Coyle K.
      • Basen-Enquist K.
      • Kirby D.
      • et al.
      Safer choices: Reducing teen pregnancy, HIV and STDs.
      ,
      • St. Lawrence J.S.
      • Jefferson K.W.
      • Alleyne E.
      • et al.
      Cognitive-behavioral intervention to reduce African American adolescents’ risk for HIV infection.
      ].
      Figure thumbnail gr1
      Figure 1Characteristics of effective curriculum-based programs.
      Although nearly all of the effective curricula incorporated nearly all of the effective characteristics, and although curricula with nearly all of the characteristics were highly likely to be effective, having most of the 17 characteristics present in a curriculum did not ensure significant changes in reported behavior. In addition, a few curricula that did not appear to incorporate all 17 characteristics nevertheless had a positive impact.
      It should also be recognized that these characteristics of effective programs are not the only factors that determine whether or not programs will have an impact on behavior. Other factors, such as the saliency of unintended pregnancy, HIV or other STDs and the existing knowledge, values, attitudes, and skills of young also have an impact. Thus, for example, if HIV is a very salient issue in a community and youth in that community lack basic information about how HIV is transmitted, the chances of infection during unprotected sex, and methods of protection, then programs that provide this basic information may have an impact on behavior, even if they do not incorporate all of the 17 characteristics.
      The 17 characteristics can logically be divided into three categories, namely those describing: (1) the development of the curricula, (2) the overall design and teaching strategies of the curricula themselves, and (3) the implementation of the curricula. As noted above, they are presented in Figure 1.
      These characteristics can be used to assess and select curricula [
      • Kirby D.
      • Rolleri L.
      • Wilson M.M.
      ], to adapt or improve them and even to develop them from scratch. They can also be used to guide implementation.

      Conclusions and Recommendations

      Many of these studies had significant limitations. For example, few described their respective programs adequately; none studied programs for youth engaging in same-sex behavior; some had problems with implementation; a few had relatively weak quasi-experimental designs; an unknown number had measurement problems; many were statistically underpowered; most did not adjust for multiple tests of significance; few measured impact on either STD or pregnancy rates; and still fewer measured impact on STD or pregnancy rates with biomarkers. And, of course, there are inherent publication biases that affect the publication of studies—researchers are more likely to try to publish articles if positive results support their theories and programs and journals are more likely to accept articles for publication if results are positive. Fortunately, some of these biases counteract each other.
      Despite these limitations, the evidence for the positive impact on behavior of curriculum- and group-based sex and HIV education programs for adolescents and young adults is quite strong and encouraging. Two thirds of the programs had a significant positive impact on behavior. Many either delayed or reduced sexual activity or increased condom or contraceptive use or both. At least 10 interventions had long-term behavioral effects lasting 2 or more years; some lasted for close to 3 or more years—as long as the effects were measured. Most programs also increased psychosocial mediating factors that are known to be related to sexual behavior. These studies help explain how these programs are effective.
      The evidence is also strong that these programs in general did not have negative effects. In particular, they did not increase sexual behavior, as some people have feared they might. Of the 52 studies that measured impact on initiation of sex, only one significantly hastened the initiation of sex. Given the large number of studies and tests of significance for that outcome, that could have occurred by chance. The few other scattered negative findings among both abstinence-only and comprehensive sex and HIV education programs may also have occurred by chance. The evidence is dramatically stronger that these programs had positive effects on sexual behavior.
      The effects of these programs were quite robust. They were just as likely, if not more likely, to be effective in developing countries as they were to be effective in the U.S. or other developed countries. They were effective in urban and rural areas, low- and middle-income communities, and school and community settings, with advantaged and disadvantaged youth, males and females, different racial and ethnic groups, younger and older youth, and sexually experienced and inexperienced youth. There is some indication that they were especially effective with youth who were most likely to engage in unprotected sex with multiple partners and thus were at highest risk of HIV, other STDs and pregnancy. Of course, the exact same program was not implemented with all of these groups; rather programs were appropriately designed or tailored for some of these groups.
      Robustness was also demonstrated by replication studies. When three programs were replicated with fidelity in different locations throughout the United States, but in the same type of setting, the original positive effects were confirmed. This is very encouraging and suggests that effective programs can remain effective when they are implemented by people in other communities.
      Given that many programs reduced sexual behavior and/or also increased condom or contraceptive use, they logically would reduce both sexually transmitted disease and pregnancy. The results of the few studies that measured impact on STD or pregnancy, however, did not produce many significant positive effects. The lack of consistent positive effects may have been caused, in part, by sample sizes that were too small, by other methodological limitations, by significant changes in behavior that were too small or too short term to produce marked changes in STD or pregnancy, or possible failure to change those behaviors that have the strongest impact on STD or pregnancy rates.
      Thus, while these programs alone cannot solve the problems of STD, HIV, and unintended pregnancy, many of them can change sexual and protective behaviors in desired directions and they can be an important component in larger more comprehensive initiatives.
      These conclusions support several programmatic and research conclusions:
      • Communities should implement curriculum-based sex and HIV education programs, preferably those proven to be effective with similar populations or those incorporating the 17 characteristics of effective programs.
      • Because these programs can reduce sexual risk-taking by a modest amount, communities should not rely solely on these programs to address problems of HIV, other STDs, and pregnancy, but should view them as an important component in a larger initiative that can reduce sexual risk-taking behavior to some degree.
      • More rigorous studies of promising programs need to be conducted, especially in developing countries and with groups at highest risk, because there are gaps in these areas in the existing literature.
      • Evaluations can and should use randomized experimental designs. They have been used very successfully even in the poorest regions of the world.
      • Sample sizes should be sufficiently large to have adequate statistical power for important statistical analyses, including those among subgroups. Conducting studies that are substantially underpowered is unfair to their respective programs and may mislead the field.
      • Laboratory tests rather than self-reported data have been used for measuring pregnancy and STD rates, and should be used whenever feasible. These studies are particularly important given that many programs have changed behavior, but few have changed pregnancy and STD rates. This apparent inconsistency needs to be further understood.
      • Researchers should determine more rigorously which mediating factors have the greatest impact on behavior in different cultures and which educational strategies and activities are most effective at changing these factors both across and within cultures. More generally, studies should try to assess which of the 17 characteristics are most important and what kinds of adaptations can be safely made without jeopardizing effectiveness.
      • Researchers should always try to publish negative results, provided that the studies are well done, so that the literature does not become biased.
      • Published results of evaluations should provide more complete descriptions of their programs so that reviews can better assess their characteristics and understand why some programs were effective and other were not.
      • Formal meta-analyses of all of these studies should be conducted so that they can overcome some of the limitations of the individual studies (e.g., insufficient statistical power).
      If these recommendations are implemented, the success of these programs and our knowledge of these programs will continue to progress, as they have for the last 25 years.

      Acknowledgments

      Financial support for this research was provided by the United States Agency for International Development (USAID) through Family Health International (FHI)/YouthNet Project. The views reflected in this article do not necessarily reflect those of USAID, FHI, or ETR Associates.

      References

        • Guttmacher Institute
        U.S. Teenage Pregnancy Statistics National and State Trends and Trends by Race and Ethnicity. Guttmacher Institute, New York2006
        • Weinstock H.
        • Berman S.
        • Cates W.
        Sexually transmitted diseases among American youth: Incidence and prevalence estimates.
        Perspect Sex Reprod Health. 2004; 36: 6-10
      1. United Nations. Demographic Yearbook, 2002. Available at: http://unstats.un.org/unsd/demographic/products/dyb/dybpub2002.htm.

        • Health Protection Agency
        Diagnoses of selected STIs by region, sex and age group United Kingdom: 1995–2004. 2005 (London)
      2. Lloyd C.B. Growing up Global: The Changing Transitions to Adulthood in Developing Countries. The National Academies Press, Washington, D.C2005
        • Ross D.
        • Dick B.
        • Ferguson J.
        Preventing HIV/AIDS in Young People: A systematic review of the evidence from developing countries. WHO, Geneva2006
        • Kirby D.
        Emerging Answers: Research Findings on Programs to Reduce Teen Pregnancy. The National Campaign to Prevent Teen Pregnancy, Washington D.C2001
        • Mullen P.
        • Ramierez G.
        • Strouse D.
        • et al.
        Meta-analysis of the effects of behavioral HIV prevention interventions on the sexual risk behavior of sexually experienced adolescents in controlled studies in the United States.
        J AIDS. 2002; 30: S94-S105
        • Gallant M.
        • Maticka-Tyndale E.
        School-based HIV prevention programmes for African youth.
        Soc Sci Med. 2004; 58: 1337-1351
      3. FOCUS on Young Adults, Advancing Young Adult Reproductive Health: Actions for the Next Decade. Pathfinder, Washington, D.C2001
        • Aarons S.
        • Jenkins R.R.
        • Raine T.R.
        • et al.
        Postponing sexual intercourse among urban junior high school students?.
        J Adolesc Health. 2000; 27: 236-247
        • Agha S.
        • Van Rossem R.
        Impact of a school-based peer sexual health intervention on normative beliefs, risk perceptions, and sexual behavior of Zambian adolescents.
        J Adolesc Health. 2004; 34: 441-452
        • Antunes M.
        • Stall R.
        • Paiva V.
        • et al.
        Evaluating an AIDS sexual risk reduction program for young adults in public night schools in Sào Paulo, Brazil.
        AIDS. 1997; 11: S121-S127
        • Aten M.
        • Siegel D.
        • Enaharo M.
        • et al.
        Keeping middle school students abstinent: Outcomes of a primary prevention intervention.
        J Adolesc Health. 2002; 31: 70-78
        • Baker S.
        • Rumakom P.
        • Sartsara S.
        • et al.
        Evaluation of an HIV/AIDS program for college students in Thailand. The Population Council, Washington, D.C2003
        • Baldwin J.
        • Whiteley S.
        • Baldwin J.
        Changing AIDS- and fertility-related behavior: The effectiveness of sexual education.
        J Sex Res. 1990; 27: 245-262
      4. Blake S, Ledsky R, Lohrmann D, et al. Overall and differential impact of an HIV/STD prevention curriculum for adolescents. Submitted for publication.

      5. Borawski E, Trapl E, Goodwin M. Teaching HIV Prevention in Schools: Taking Be Proud! Be Responsible! to the Suburbs. Paper presented at: Psychosocial Workshop of the Population Association of America; Philadelphia, PA, March 29–30, 2005.

        • Borawski E.
        • Trapl E.
        • Lovegreen L.
        • et al.
        Effectiveness of abstinence-only intervention in middle school teens.
        Am J Health Behav. 2005; 29: 423-434
        • Boyer C.
        • Shafer M.
        • Shaffer R.
        • et al.
        Prevention of sexually transmitted diseases and HIV in young military men: Evaluation of a cognitive-behavioral skills-building intervention.
        Sex Transm Dis. 2001; 28: 349-355
        • Boyer C.
        • Shafer M.
        • Shaffer R.
        • et al.
        Evaluation of a cognitive-behavioral, group, randomized controlled intervention trial to prevent sexually transmitted infections and unintended pregnancies in young women.
        Prev Med. 2005; 40: 420-431
        • Boyer C.
        • Shafer M.
        • Tschann J.
        Evaluation of a knowledge- and cognitive-behavioral skills-building intervention to prevent STDs and HIV infection in high school students.
        Adolescence. 1997; 32: 25-42
        • Bryan A.
        • Aiken L.
        • West S.
        Increasing condom use: Evaluation of a theory-based intervention to prevent sexually transmitted diseases in young women.
        Health Psychol. 1996; 15: 371-382
        • Cabezon C.
        • Vigil P.
        • Rojas I.
        • et al.
        Adolescent pregnancy prevention: An abstinence-centered randomized controlled intervention in a Chilean public high school.
        J Adolesc Health. 2005; 36: 64-69
        • Caron F.
        • Godin G.
        • Otis J.
        • Lambert L.
        Evaluation of a theoretically based AIDS/STD peer education program on postponing sexual intercourse and on condom use among adolescents attending high school.
        Health Educ Res. 2004; 19: 185-197
        • Coyle K.
        • Basen-Enquist K.
        • Kirby D.
        • et al.
        Safer choices: Reducing teen pregnancy, HIV and STDs.
        Public Health Rep. 2001; 116: 82-93
        • Coyle K.
        • Basen-Enquist K.
        • Kirby D.
        • et al.
        Short-term impact of Safer Choices: A multi-component school-based HIV, other STD and pregnancy prevention program.
        J School Health. 1999; 69: 181-188
        • Coyle K.
        • Kirby D.
        • Marin B.
        • et al.
        Draw the Line/Respect the Line: A randomized trial of a middle school intervention to reduce sexual risk behaviors.
        Am J Public Health. 2004; 94: 843-851
        • DiClemente R.
        • Wingood G.
        • Harrington K.
        • et al.
        Efficacy of an HIV prevention intervention for African-American adolescent girls.
        JAMA. 2004; 292: 171-179
        • Diez E.
        • Juárez O.
        • Nebot M.
        • et al.
        Effects on attitudes, knowledge, intentions and behaviour of an AIDS prevention programme targeting secondary school adolescents.
        Promotion Educ. 2000; 7: 17-22
        • Eggleston E.
        • Jackson J.
        • Rountree W.
        • Pan Z.
        Evaluation of a sexuality education program for young adolescents in Jamaica.
        Revista Panamericana de Salud Pública/Pan Am J Public Health. 2000; 7: 102-112
        • Eisen M.
        • Zellman G.
        • McAlister A.
        Evaluating the impact of a theory-based sexuality and contraceptive education program.
        Fam Plann Perspect. 1990; 22: 261-271
        • Ekstrand M.
        • Siegel D.S.
        • Nido V.
        • et al.
        Peer-led AIDS prevention delays onset of sexual activity and changes peer norms among urban junior high school students. XI International Conference on AIDS, Vancouver, Canada1996
        • Erulkar A.
        • Ettyang L.
        • Onoka C.
        • et al.
        Behavior change evaluation of a culturally consistent reproductive health program for young Kenyans.
        Int Fam Plann Perspect. 2004; 30: 58-67
        • Fawole I.
        • Asuzu M.
        • Oduntan S.
        • Brieger W.
        A school-based AIDS education programme for secondary school students in Nigeria: A review of effectiveness.
        Health Educ Res. 1999; 14: 675-683
        • Fisher J.
        • Fisher W.
        • Bryan A.
        • Misovich S.
        Information-motivation-behavioral skills model-based HIV risk behavior change intervention for inner-city high school youth.
        Health Psychol. 2002; 21: 177-186
        • Gillmore M.
        • Morrison D.
        • Richey C.
        • et al.
        Effects of a skill-based intervention to encourage condom use among high risk heterosexually active adolescents.
        AIDS Educ Prev. 1997; 9: 22-43
        • Girls Incorporated
        Truth, Trust and Technology: New research on preventing adolescent pregnancy. Girls Incorporated, New York1991
        • Girls Incorporated
        Girls Incorporated Preventing Adolescent Pregnancy: A Program Development and Research Project. Volume 2: Narrative Description of the Preventing Adolescent Pregnancy Project. Girls Incorporated, Indianapolis1991
        • Goertzel T.
        • Bluenond-Langner M.
        What is the impact of a campus AIDS education course?.
        College Health. 1991; 40: 87-92
        • Gottsegen E.
        • Philliber W.
        Impact of a male sexuality responsibility program on young males.
        Adolescence. 2001; 36: 427-433
        • Harrington N.
        • Giles S.
        • Hoyle R.
        • et al.
        Evaluation of the All Stars character education and problem behavior prevention program: Effects on mediator and outcome variables for middle school students.
        Health Educ Behav. 2001; 28: 533-546
        • Harvey B.
        • Stuart J.
        • Swan T.
        Evaluation of a drama-in-education programme to increase AIDS awareness in South African high schools: A randomized community intervention trial.
        J STD AIDS. 2000; 11: 105-111
        • Harvey B.
        • Stuart J.
        • Swan T.
        Statistical methods and the evaluation of school-based AIDS education in Africa.
        Int J STD AIDS. 2000; 11 (reply): 553-554
        • Howard M.
        Delaying the start of intercourse among adolescents.
        Adolesc Med. 1992; 3: 181-193
        • Howard M.
        • McCabe J.
        Helping teenagers postpone sexual involvement.
        Plann Perspect. 1990; 22: 21-26
        • Hubbard B.M.
        • Giese M.L.
        • Rainey J.
        A replication of Reducing the Risk, a theory-based sexuality curriculum for adolescents.
        J School Health. 1998; 68: 243-247
      6. Jemmott III J. Effectiveness of an HIV/STD risk-reduction intervention implemented by nongovernmental organizations: A randomized controlled trial among adolescents. American Psychological Association Annual Conference, 2005.

        • Jemmott III, J.
        • Jemmott L.
        • Braverman P.
        • et al.
        HIV/STD risk reduction interventions for African American and Latino adolescent girls at an adolescent medicine clinic.
        Arch Pediatr Adolesc Med. 2005; 159: 440-449
        • Jemmott III, J.
        • Jemmott L.
        • Fong G.
        Reductions in HIV risk-associated sexual behaviors among black male adolescents: Effects of an AIDS prevention intervention.
        Am J Public Health. 1992; 82: 372-377
        • Jemmott III, J.
        • Jemmott L.
        • Fong G.
        • et al.
        Reducing HIV risk-associated sexual behaviors among African American adolescents: Testing the generality of intervention effects.
        Am J Commun Psychol. 1999; 27: 161-187
        • Jemmott III, J.
        • Jemmott L.
        • Fong G.
        Abstinence and safer sex: HIV risk-reduction interventions for African-American adolescents: A randomized controlled trial.
        JAMA. 1998; 279: 1529-1536
        • Kinsler J.
        • Sneed C.
        • Morisky D.
        • Ang A.
        Evaluation of a school-based intervention for HIV/AIDS prevention among Belizean adolescents.
        Health Educ Res. 2004; 19: 730-738
        • Kirby D.
        • Barth R.
        • Leland N.
        • Fetro J.
        Reducing the Risk: Impact of a new curriculum on sexual risk-taking.
        Fam Plann Perspect. 1991; 23: 253-263
        • Kirby D.
        • Baumler E.
        • Coyle K.
        • et al.
        The “Safer Choices” intervention: Its impact on the sexual behaviors of different subgroups of high school students.
        J Adolesc Health. 2004; 35: 442-452
        • Kirby D.
        • Korpi M.
        • Adivi C.
        • Weissman J.
        An impact evaluation of Project SNAPP: An AIDS and pregnancy prevention middle school program.
        AIDS Educ Prev. 1997; 9: 44-61
        • Kirby D.
        • Korpi M.
        • Barth R.P.
        • et al.
        Evaluation of Education Now and Babies Later (ENABL): Final Report. Family Welfare Research Group, Berkeley, CA1995
        • Kirby D.
        • Korpi M.
        • Barth R.P.
        • et al.
        The impact of the Postponing Sexual Involvement curriculum among youths in California.
        Fam Plann Perspect. 1997; 29: 100-108
        • Klepp K.
        • Ndeki S.
        • Leshabari M.
        • et al.
        AIDS education in Tanzania: Promoting risk reduction among primary school children.
        J Public Health. 1997; 87: 1931-1936
        • Klepp K.
        • Ndeki S.
        • Seha A.
        • et al.
        AIDS education for primary school children in Tanzania: An evaluation study.
        AIDS. 1994; 8: 1157-1162
        • Kvalem I.
        • Sundet J.
        • Rivø K.
        • et al.
        The effect of sex education on adolescents’ use of condoms: Applying the Solomon four-group design.
        Health Educ Quart. 1996; 23: 34-47
        • LaChausse R.
        Evaluation of the Positive Prevention HIV/STD Curriculum for Students Grades 9–12.
        Am J Health Educ. 2006; 37: 203-209
        • Levy S.R.
        • Perhats C.
        • Weeks K.
        • et al.
        Impact of a school-based AIDS prevention program on risk and protective behavior for newly sexually active students.
        J School Health. 1995; 65: 145-151
        • Li X.
        • Stanton B.
        • Freigelman S.
        • Galbraith J.
        Unprotected sex among African American adolescents: A three-year study.
        J Natl Med Assoc. 2002; 94: 789-796
        • Lieberman L.D.
        • Gray H.
        • Wier M.
        • et al.
        Long-term outcomes of an abstinence-based, small-group pregnancy prevention program in New York City schools.
        Fam Plann Perspect. 2000; 32: 237-245
        • Little C.B.
        • Rankin A.
        An evaluation of the Postponing Sexual Involvement curriculum among upstate New York eighth graders.
        Sociol Forum. 2001; 15: 4
        • Magura S.
        • Kang S.
        • Shapiro J.L.
        Outcomes of intensive AIDS education for male adolescent drug users in jail.
        J Adolesc Health. 1994; 15: 457-463
        • Main D.S.
        • Iverson D.C.
        • McGloin J.
        • et al.
        Preventing HIV infection among adolescents: Evaluation of a school-based education program.
        Prev Med. 1994; 23: 409-417
        • Martinez-Donate A.
        • Melbourne F.
        • Zellner J.
        • et al.
        Evaluation of two school-based HIV prevention interventions in the border city of Tijuana, Mexico.
        J Sex Res. 2004; 41: 267-278
        • Maticka-Tyndale E.
        • Brouillard-Coyle C.
        • Gallant M.
        • et al.
        Primary School Action for Better Health: 12–18 Month Evaluation — Final Report on PSABH Evaluation in Nyanza and Rift Valley. University of Windsor, Windsor, Canada2004
        • McCauley A.
        • Pick S.
        • Givaudan M.
        Programming for HIV Prevention in Mexican Schools. Population Council, Washington, DC2004
        • Mellanby A.
        • Phelps F.
        • Crichton N.
        • Tripp J.
        School sex education: An experimental programme with educational and medical benefit.
        Br Med J. 1995; 311: 414-417
        • Mitchel-DiCenso A.
        • Thomas B.H.
        • Devlin M.C.
        • et al.
        Evaluation of an educational program to prevent adolescent pregnancy.
        Health Educ Behav. 1997; 24: 300-312
        • Moberg D.P.
        • Piper D.L.
        An outcome evaluation of Project Model Health: A middle school health promotion program.
        Health Educ Quart. 1990; 17: 37-51
        • Moberg D.P.
        • Piper D.L.
        The Healthy for Life Project: Sexual risk behavior outcomes.
        AIDS Educ Prevent. 1998; 10: 128-148
        • Murray N.
        • Toledo V.
        • Luengo X.
        • et al.
        An evaluation of an integrated adolescent development program for urban teenagers in Santiago, Chile. Futures Group, Washington, DC2000
        • Nicholson H.
        • Postrado L.
        A comprehensive age-phased approach. Girls Incorporated, New York1992
        • Nicholson H.J.
        • Postrado L.T.
        Truth, trust and technology: New research on preventing adolescent pregnancy. Girls Incorporated, New York1991
        • Nicholson H.J.
        • Postrado L.T.
        Girls Incorporated preventing adolescent pregnancy: A program development and research project. Girls Incorporated, New York1991
        • Postrado L.T.
        • Nicholson H.J.
        Effectiveness in delaying the initiation of sexual intercourse of girls aged 12–14: Two components of the Girls Incorporated Preventing Adolescent Pregnancy Program.
        Youth Soc. 1992; 21: 356-379
        • Reddy P.
        • James S.
        • McCauley A.
        Programming for HIV Prevention in South African Schools. Population Council, Washington, DC2003
        • Ross D.
        MEMA Kwa Vijana: Randomized controlled trial of an adolescent sexual health programme in rural Mwanza, Tanzania. London School of Hygiene and Tropical Medicine, London2003
        • Rotheram-Borus M.
        • Gwadz M.
        • Fernandez M.
        • Srinivasan S.
        Timing of HIV interventions on reductions in sexual risk among adolescents.
        Am J Commun Psychol. 1998; 26: 73-96
        • Rotheram-Borus M.
        • Lee M.
        • Murphy D.
        • et al.
        Efficacy of a prevention intervention for youths living with HIV.
        Am J Public Health. 2001; 91: 400-405
        • Rotheram-Borus M.
        • Murphy D.
        • Fernandez M.
        • Srinivasan S.
        • et al.
        A brief HIV intervention for adolescents and young adults.
        Am J Orthopsychiatry. 1998; 68: 553-564
        • Rotheram-Borus M.
        • Song J.
        • Gwadz M.
        • et al.
        Reductions in HIV risk among runaway youth.
        Prev Sci. 2003; 4: 173-187
        • Rotheram-Borus M.J.
        • Koopman C.
        • Haigners C.
        • Davies M.
        Reducing HIV sexual risk behaviors among runaway adolescents.
        JAMA. 1991; 266: 1237-1241
        • Schaalma H.
        • Kok G.
        • Bosker R.
        • et al.
        Planned development and evaluation of AIDS/STD education for secondary school students in the Netherlands: Short-term effects.
        Health Educ Quart. 1996; 23: 469-487
        • Seidman M.
        • Vigil P.
        • Klaus H.
        • et al.
        Fertility awareness education in the schools: A pilot program in Santiago Chile, American Public Health Association Annual Meeting, San Diego, California. 1995
        • Siegel D.
        • Aten M.
        • Enaharo M.
        Long-term effects of a middle school- and high school-based human immunodeficiency virus sexual risk prevention intervention.
        Arch Pediatr Adolesc Med. 2001; 155: 1117-1126
        • Siegel D.
        • DiClemente R.
        • Durbin M.
        • et al.
        Change in junior high school students’ AIDS-related knowledge, misconceptions, attitudes, and HIV-prevention behaviors: Effects of a school-based intervention.
        AIDS Educ Prev. 1995; 7: 534-543
        • Slonim-Nevo V.
        • Auslander W.F.
        • Ozawa M.N.
        • Jung K.G.
        The long-term impact of AIDS-preventive interventions for delinquent and abused adolescents.
        Adolescence. 1996; 31: 409-421
        • Smith P.
        • Weinman M.
        • Parrilli J.
        The role of condom motivation education in the reduction of new and reinfection rates of sexually transmitted diseases among inner-city female adolescents.
        Patient Educ Counsel. 1997; 31: 77-81
        • St. Lawrence J.
        • Crosby R.
        • Brasfield T.
        • O’Bannon III, R.
        Reducing STD and HIV risk behavior of substance-dependent adolescents: A randomized controlled trial.
        J Consult Clin Psychol. 2002; 70: 1010-1021
        • St. Lawrence J.S.
        • Jefferson K.W.
        • Alleyne E.
        • et al.
        Cognitive-behavioral intervention to reduce African American adolescents’ risk for HIV infection.
        J Consult Clin Psychol. 1995; 63: 221-237
        • St. Pierre T.L.
        • Mark M.M.
        • Kaltreider D.L.
        • Aikin K.J.
        A 27-month evaluation of a sexual activity prevention program in Boys & Girls Clubs across the nation.
        Fam Relat. 1995; 44: 69-77
        • Stanton B.
        • Guo J.
        • Cottrell L.
        • et al.
        The complex business of adapting effective interventions to new populations: An urban to rural transfer.
        J Adolesc Health. 2005; 37: 17-26
        • Stanton B.
        • Li X.
        • Galbraith J.
        • et al.
        Sexually transmitted diseases, human immunodeficiency virus and pregnancy prevention.
        Arch Pediatr Adolesc Med. 1996; 150: 17-24
        • Stanton B.
        • Li X.
        • Kahihuata J.
        • et al.
        Increased protected sex and abstinence among Namibian youth following a HIV risk-reduction intervention: A randomized, longitudinal study.
        AIDS. 1998; 12: 2473-2480
        • Stanton B.
        • Li X.
        • Ricardo I.
        • et al.
        A randomized, controlled effectiveness trial of an AIDS prevention program for low-income African-American youths.
        Arch Pediatr Adolesc Med. 1996; 150: 363-372
        • Stephenson J.
        • Strange V.
        • Forrest S.
        • et al.
        Pupil-led sex education in England (RIPPLE study): Cluster-randomised intervention trial.
        Lancet. 2004; 364: 338-346
      7. Thomas B, Mitchell A, Devlin M, et al, (eds.). Small group sex education at school: The McMaster Teen Program. In: Miller BC, Card JJ, Paikoff RL, Peterson JL, (eds). Preventing Adolescent Pregnancy. Newbury Park, CA: Sage, 1992.

        • Turner J.
        • Korpita E.
        • Mohn L.
        • Hill W.
        Reduction in sexual risk behaviors among college students following a comprehensive health education intervention.
        College Health. 1993; 41: 187-193
        • Villarruel A.
        • Jemmott III, J.
        • Jemmott L.
        A randomized controlled trial testing an HIV prevention intervention for Latino youth.
        Arch Pediatr Adolesc Med. 2006; 160: 772-777
        • Walter H.J.
        • Vaughn R.D.
        AIDS risk reduction among a multiethnic sample of urban high school students.
        JAMA. 1993; 270: 725-730
        • Warren W.K.
        • King A.J.C.
        Development and evaluation of an AIDS/STD/sexuality program for grade 9 students. Social Program Evaluation Group, Kingston, Ontario1994
        • Weed S.E.
        • Olsen J.A.
        • DeGaston J.
        • Prigmore J.
        Predicting and changing teen sexual activity rates: A comparison of three Title XX programs. Office of Adolescent Pregnancy Programs, Washington, DC1992 (December)
        • Weeks K.
        • Levy S.R.
        • Gordon A.K.
        • et al.
        Does parental involvement make a difference?.
        AIDS Educ Prev. 1997; 9: 90-106
        • Wenger N.
        • Greenberg J.
        • Hilbourne L.
        • et al.
        Effect of HIV antibody testing and AIDS education on communication about HIV risk and sexual behavior: A randomized, controlled trial in college students.
        Ann Intern Med. 1992; 117: 905-911
        • Wight D.
        • Raab G.
        • Henderson M.
        • et al.
        The limits of teacher-delivered sex education: Interim behavioral outcomes from a randomised trial.
        Br Med J. 2002; 324: 1430-1433
      8. Zimmerman R, Cupp P, Hansen G, et al. The effects of a school-based HIV and pregnancy prevention program in rural Kentucky. J School Health. In press.

      9. Zimmerman R, Donohew L, Sionéan C, et al. Effects of a school-based, theory driven HIV and pregnancy prevention curriculum. Perspect Sex Reprod Health. In press.

        • Kirby D.
        No Easy Answers: Research Findings on Programs to Reduce Teen Pregnancy. National Campaign to Prevent Teen Pregnancy, Washington, DC1994
        • Sonenstein F.
        Measuring sexual risk behaviors. American Enterprise Institute, Washington, DC1996
        • Plummer M.
        • Ross D.
        • Wight D.
        • et al.
        “A bit more truthful”: The validity of adolescent sexual behaviour data collected in rural northern Tanzania using five methods.
        Sex Transm Infect. 2004; 80: ii49-ii56
        • St. Lawrence J.
        • Crosby R.
        • Belcher L.
        • et al.
        Sexual risk reduction and anger management interventions for incarcerated male adolescents: A randomized controlled trial of two interventions.
        J Sex Educ Ther. 1999; 24: 9-17
        • Kirby D.
        • Lepore G.
        • Ryan J.
        Sexual risk and protective factors: Factors affecting teen sexual behavior, pregnancy, childbearing and sexually transmitted disease: Which are important? National Campaign to Prevent Teen Pregnancy, Washington, D.C2005
        • Kirby D.
        • Rolleri L.
        • Wilson M.M.
        A Tool to Assess the Characteristics of Effective Sex and STD/HIV Education Programs. Healthy Teen Network, Washington, D.C2006