Using randomized designs to evaluate client-centered programs to prevent adolescent pregnancy. Adolescent pregnancy prevention: An abstinence-centered randomized controlled intervention in a Chilean public high school. A computer-based approach to preventing pregnancy, STD, and HIV in rural adolescents. Tailored intervention to increase dual-contraceptive method use: a randomized trial to reduce unintended pregnancies and sexually transmitted infections. Preventing pregnancy and improving health care access among teenagers: an evaluation of the children's aid society-carrera program. Evaluation of an educational program to prevent adolescent pregnancy. Intervening with couples: assessing contraceptive outcomes in a randomized pregnancy and HIV/STD risk reduction intervention trial. Pregnancy and STD prevention counseling using an adaptation of motivational interviewing: a randomized controlled trial. Evaluating the impact of a theory-based sexuality and contraceptive education program.
Interventions to prevent adolescent pregnancy (primarily curriculum-based programs) have not produced convincing evidence as to their success. Moreover, many evaluation approaches have been inadequate to assess program effectiveness. Therefore, rigorous evaluation of different kinds of interventions may help identify potentially effective strategies to prevent adolescent pregnancy.
                An experimental design, in which clients were randomized to treatment and control groups, was used to evaluate the effects of a "client-centered" approach to reducing pregnancy among high-risk young people in seven communities in Washington State. Four projects served 1,042 youth (clients aged 9-13), and three served 690 teenagers (primarily clients aged 14-17). Projects offered a wide variety of services tailored to individual clients' needs, including counseling, mentoring and advocacy.
                On average, clients in the treatment group at youth sites received 14 hours of service, and their teenage counterparts received 27 hours; controls received only 2-5 hours of service. At one youth site, clients were less likely to intend to have intercourse after the intervention than before; at another, they became less likely to intend to use substances. Clients at one teenage project reported reduced sexual behavior and improved contraceptive use after receiving services; teenagers at another site reported reduced sexual intentions and drug use, and a greater intention to use contraceptives. The programs showed no other effects on factors that place young people at risk of becoming pregnant, including their sexual values and educational aspirations, communication with their parents (measured at youth sites only), and sexual and contraceptive behavior (assessed for teenagers only).
                High-risk clients likely need considerably more intervention time and more intensive services than programs normally provide. Rigorous evaluation designs allow continued assessment that can guide program modifications to maximize effects. To evaluate the efficacy of an abstinence-centered sex education program in adolescent pregnancy prevention, the TeenSTAR Program was applied in a high school in Santiago, Chile.
                A total of 1259 girls from a Santiago high school were divided into three cohorts depending on the year they started high school: the 1996 cohort of 425 students, which received no intervention; the 1997 cohort, in which 210 students received an intervention and 213 (control group) did not; and the 1998 cohort, in which 328 students received an intervention and 83 (control group) did not. Students were randomly assigned to control and intervention groups in these cohorts, before starting with the program. We conducted a prospective, randomized study using the application of the TeenSTAR sex education program during the first year of high school to the intervention groups in the 1997 and 1998 cohorts. All cohorts were followed up for 4 years; pregnancy rates were recorded and subsequently contrasted in the intervention and control groups. Pregnancy rates were measured and Risk Ratio with 95% confidence interval were calculated for intervention and control groups in each cohort.
                Pregnancy rates for the intervention and control groups in the 1997 cohort were 3.3% and 18.9%, respectively (RR: 0.176, CI: 0.076-0.408). Pregnancy rates for the intervention and control groups in the 1998 cohort were 4.4% and 22.6%, respectively (RR 0.195, CI: 0.099-0.384).
                The abstinence-centered TeenSTAR sex education intervention was effective in the prevention of unintended adolescent pregnancy. A computer- and Internet-based intervention was designed to influence several variables related to the prevention of pregnancy, sexually transmitted diseases (STDs), and human immunodeficiency virus (HIV) in rural adolescents. The intervention was guided by the extended parallel process model and was evaluated using a pretest-post-test control group design with random assignment at the school level. Three hundred and twenty-six tenth-grade males and females enrolled in two rural Appalachian public high schools completed the survey at both points in time. Results indicate the vast majority (88.5%) of students in the experimental school completed at least one activity (M = 3.46 for those doing at least one activity). Further, both the overall program and all but one of the activities were rated positively by participants. Regarding the effects of the intervention, results indicate that students in the experimental school were less likely to initiate sexual activity and had greater general knowledge, greater condom negotiation self-efficacy, more favorable attitudes toward waiting to have sex, and greater situational self-efficacy than in the control school. In tandem, the results suggest that the computer-based programs may be a cost-effective and easily replicable means of providing teens with basic information and skills necessary to prevent pregnancy, STDs, and HIV. The objective of the study was to determine whether a transtheoretical model-tailored expert system intervention increases dual-method contraceptive use, compared with a nontailored educational intervention.
                We performed a randomized clinical trial of 542 women at high risk for sexually transmitted infections (STIs) and unintended pregnancy. The intervention group received computer-based tailored feedback using a multimedia program. The control group received general contraceptive information and nontailored advice.
                Participants in the intervention group were more likely to report use of dual contraceptive methods during follow-up (adjusted hazard rate ratio 1.70, 95% confidence interval 1.09, 2.66), compared with controls. However, there were no differences in the rates of incident STI or unintended pregnancy between the 2 groups.
                The computer-based transtheoretical model-tailored intervention resulted in a 70% increase in reported dual-method contraceptive use in a group of women at high risk for STIs and unintended pregnancy. Inconsistent use of dual methods may explain the lack of effect on unintended pregnancy rates and incident STIs. Despite the recent declines in rates of teenage pregnancy, relatively little is known about the few programs that have been successful in reducing adolescent pregnancy.
                Six agencies in New York City each randomly assigned 100 disadvantaged 13-15-year-olds to their usual youth program or to the intervention being tested--the Children's Aid Society-Carrera program, a year-round afterschool program with a comprehensive youth development orientation. Both program and control youth were followed for three years. Multivariate regression analyses assessed the effects of program participation on the odds of current sexual activity, use of a condom along with a hormonal contraceptive, pregnancy and access to good health care.
                Seventy-nine percent of participants remained in the program for three full years. Female program participants had significantly lower odds than controls of being sexually active (odds ratio, 0.5) and of having experienced a pregnancy (0.3). They had significantly elevated odds of having used a condom and a hormonal method at last coitus (2.4). However, participation in the program created no significant impact on males' sexual and reproductive behavior outcomes. Nonetheless, program participants of both genders had elevated odds of having received good primary health care (2.0-2.1).
                This program is one of only four whose evaluation has successfully documented declines in teenage pregnancy using a random-assignment design. Better outcomes among males may be achieved if programs reach them even earlier than their teenage years. The authors evaluated the effectiveness of a school-based sex education program in decreasing rates of sexual intercourse, improving birth control use, and decreasing the incidence of pregnancies among teenagers 16 years of age and younger. Twenty-one schools received either the McMaster Teen Program or the conventional didactic sex education program. Preprogram, the mean age of the students was 12.6 years. There were no statistically significant differences between groups in time to first sexual activity for males, chi 2(1) = 2.93, p = 0.09; time to first sexual activity for females, chi 2(1) = 0.50, p = 0.48; and time to first pregnancy, chi 2(1) = 1.90, p = 0.17. Significantly more experimental group males reported always using birth control at year 1 (difference 8.9%; 95% confidence interval [CI] = 0.4, 17.4). Limitations of the program that may have influenced the results were the exclusion of contraception information and its short duration. This study assessed the contraceptive outcomes of the Partners Against Risk-Taking: A Networking, Evaluation and Research Study (PARTNERS). The PARTNERS project developed and evaluated a 3-session intervention to help young women and their male partners reduce their risk for unintended pregnancies, and HIV and other STDs.
                Participating couples were randomly assigned to the 3-session intervention or a 1-session information session for couples. Changes in psychosocial factors related to women's motivation to use contraception and relationship factors were assessed using analysis of variance with repeated measures. Changes in contraceptive outcomes were assessed using logistic regression with generalized estimating equations.
                Comparison of changes from baseline to 6 months among women who participated in the 3-session intervention with those who participated in the information session showed no significant intervention effect on reports of contraceptive use. Instead, contraceptive use increased in both conditions. Both groups exhibited similar changes in the psychosocial variable measuring the importance of avoiding pregnancy and in the relationship variable measuring women's participation in contraceptive decision making. Members of the intervention group, however, showed greater improvement in the psychosocial variable measuring positive expectations pertaining to partner's support for contraception.
                These findings raise questions for further investigation to better understand couples behavior, and whether and how to intervene with couples. Given levels of unintended pregnancy and STDs, an effective counseling intervention is needed to improve women's consistent use of effective prevention methods.
                A sample of 764 women aged 16-44 who were at risk of unintended pregnancy were enrolled in a randomized controlled trial in North Carolina in 2003-2004. Intervention participants received pregnancy and STD prevention counseling, adapted from motivational interviewing, both at enrollment and two months later; controls received only a session of general health counseling. Levels of contraceptive use (categorized as high, low or none on the basis of the effectiveness of the method and the consistency of use) and barriers to use were measured at two, eight and 12 months; chi-square tests were used to compare selected outcomes between the groups. Rates of unintended pregnancy and chlamydia infection were assessed over the study period.
                At baseline, 59% of all participants reported a high level of contraceptive use, 19% a low level and 22% nonuse. At two months, the proportions of intervention and control participants who had improved their level of use or maintained a high level (72% and 66%, respectively) were significantly larger than the proportions who had reported a high level of use at baseline (59% and 58%, respectively). No significant differences were found between the groups at 12 months, or between baseline and 12 months for either group. During the study, 10-11% of intervention and control participants became pregnant, 1-2% received a chlamydia diagnosis and 7-9% had another STD diagnosed.
                Repeated counseling sessions may be needed to improve contraceptive decision-making and to reduce the risk of unintended pregnancy and STDs. A controlled field study involving 1,444 adolescent males and females 13-19 years of age was performed to compare a sexuality education program based on the health belief model and social learning theory with several publicly funded community-based and school-based interventions. Among males who had never had intercourse prior to participating in the study, those in the experimental program were more likely than those in the comparison programs to maintain abstinence over the next year; there was no program effect, however, among females. Among female adolescents who initiated intercourse after the start of the study, attendees of the comparison programs were more likely to have used an effective contraceptive at most recent intercourse and to have used an effective method more consistently than were those who attended the experimental program; no such association was seen among comparable young men. Both experimental and comparison programs significantly increased the consistent use of effective methods among teenagers who had been coitally active before attending the programs. Among males, however, when preintervention contraceptive efficiency was held constant, the experimental program led to significantly greater contraceptive efficiency during the follow-up year than did the comparison programs; among females, the two approaches produced an equivalent degree of improvement. Finally, prior exposure to sexuality education was associated with greater contraceptive efficiency at the one-year follow-up among almost all sexual-experience and gender groups, regardless of the type of intervention program attended.
Combination of educational and contraceptive interventions appears to reduce unintended pregnancy among adolescents.  Evidence for program effects on biological measures is limited. The variability in study populations, interventions and outcomes of included trials, and the paucity of studies directly comparing different interventions preclude a definitive conclusion regarding which type of intervention is most effective