Much evidence has documented the disproportionately high rates of adolescent pregnancy and childbearing and early sexual activity among the siblings of pregnant and parenting teenagers. (1) Concern over this problem led to the creation of the California Adolescent Sibling Pregnancy Prevention Program (ASPPP) in 1996. The program is delivered to the brothers and sisters of pregnant and parenting teenagers at 44 nonprofit social service agencies, community-based organizations, school districts and county health departments across California. * Each program site provides a unique combination of services, including individual case management, academic guidance, training in decision-making skills, job placement, self-esteem enhancement, and contraceptive and sexuality education. To date, the program has served approximately 6,000 youths. (2)

This article presents the results of an evaluation that had two goals. First, we sought to determine whether program participants showed more favorable outcomes than comparison youths at the conclusion of the nine-month evaluation. We assessed many outcomes, including the incidence of problem behaviors known to be risk factors for teenage pregnancy, adolescents' perceived likelihood that they would engage in pregnancy-related behaviors; and rates of first intercourse, contraceptive use and pregnancy. Second, we examined whether positive outcomes were related to the content area of services received, their mode of delivery and the dosage of the intervention. The findings from these analyses will highlight which services were most effective at preventing pregnancy in this high-risk population.

METHODS

Study Design

At the initiation of the evaluation, in May 1997, approximately 3,300 youths were participating in ASPPP. (3) Because of logistic and time constraints, only a subset of active program sites were included in the evaluation. The 16 ASPPP program sites selected to participate in the evaluation ([dagger]) were serving 1,011 clients at the time, or 31% of all clients statewide.

In our selection of program sites to be included in the evaluation, we targeted those sites that would be most representative in terms of geographic region of California, area of residence (urban or rural), and clients' age and race or ethnicity. This effort was partially successful. Although the client gender composition at the selected sites was identical to that of clients served statewide (60% female and 40% male), the 16 evaluation sites were more likely than ASPPP sites overall to be located in an urban area and to serve Hispanics and clients who were younger than the average. Finally, we could not base our selection of evaluation sites on their record of services delivered, because most program sites were still developing their service profiles at the time.

The evaluation involved a group of current participants in ASPPP and a comparison group of youths not in the program. Eligibility criteria for participation in the evaluation (as either a program client or a member of the comparison group) were being aged 11-17 years and three months; having never been pregnant or caused a pregnancy; and having a biological teenage sibling (full or half) who was pregnant or parenting and enrolled in California's Adolescent Family Life Program or Cal-Learn Program. ** The adolescents in the program group needed to be currently enrolled in ASPPP. Youths eligible for ASPPP were often identified through providers' existing caseloads, since most service providers were familiar with the families and siblings of the teenagers already enrolled in their programs.

Youths who participated in the evaluation as part of the comparison group could never have been enrolled in ASPPP, and neither could any of their siblings. Comparison youths were recruited from the waiting lists at the 16 evaluation sites or by outreach, often conducted through a satellite agency of the main ASPPP office.

We expected to enroll equivalent numbers of program clients and comparison youths at each site. (The average number of clients served per site was 63; the range, 20-195.) However, some sites could not meet this expectation because of financial and personnel constraints. For example, two sites did not enroll any comparison youths, and two enrolled only a negligible number (i.e., two or three individuals).

The Sample

Overall, 1,594 youths were enrolled in the evaluation: 1,011 program clients and 583 comparison youths. Enrollment for the evaluation took approximately 20 months (May 1997 to December 1998). Posttest data were collected nine months after enrollment. Usable posttest information was obtained for 1,271 adolescents, or 80% of those originally enrolled.

Similar proportions of program clients and comparison youths completed a posttest questionnaire (81% and 77%, respectively; [chi-square]=3.7, p<.06). The proportion successfully followed up was comparable for females (81%) and males (77%), and for youths of different races or ethnicities (Hispanics, 81%; blacks, 73%; whites, 76%; and other, 79%). Moreover, the likelihood of completing the posttest questionnaire was not related to several background characteristics, including age, receipt of financial assistance and family size.

The evaluation data reflect only those youths who provided complete pretest and posttest information. Contrasting the background characteristics of program and comparison youths indicated significant differences by several demographic factors, including age and race or ethnicity. We used two procedures to make the two groups more comparable in terms of both their characteristics and sample size. First, we eliminated all participants from the four sites that provided only three or fewer comparison youths (N=95); thus, the total unweighted sample for analysis from the remaining 12 sites was 1,176, or 731 program clients and 445 comparison youths. Second, we weighted the comparison group data within four sites that provided fewer comparison youths than program youths, but left the data unweighted from the remaining eight evaluation sites; weighting brought the final sample of comparison youths to 735.

In both the program and the comparison groups, the majority of youths were Hispanic, from economically disadvantaged families and urban residents; they were, on average, nearly 14 years old (Table 1, page 63). Program clients differed significantly from comparison youths on several background variables, however. For example, a significantly higher proportion of program than comparison youths were Hispanic (77% vs. 71%) and spoke Spanish at home (59% vs. 46%). The proportion of youths whose family was receiving aid at the time was significantly higher among comparison youths (75% vs. 66%), as was the mean grade completed by the youths' mother (9.8 vs. 9.3) and the adolescents' current grade (8.3 vs. 8.1).

Program participants and comparison youths had equivalent numbers of brothers (mean, 1.9--not shown) and sisters (2.8). Moreover, youths from both the program and the comparison groups had an equivalent number of sisters who had been pregnant during adolescence (mean, 1.3) and of brothers who had fathered a child as a teenager (mean, 0.2). (Overall, 73% of the full evaluation sample had one sister who had been pregnant or given birth, 16% had two such sisters and 6% had three or more; 11% overall had one brother who had fathered a child during adolescence and 5% had two or more.)

Forty-nine percent of evaluation participants lived in the Central Valley region of California, 27% in Los Angeles County and the surrounding coastal counties, 13% in Southern California, 6% in the San Francisco Bay area and 5% in Northern California. These proportions roughly correspond to the geographic distribution of all clients served by the program.

Survey Procedures and Measures

At enrollment, all participants were interviewed about their family background and completed a 59-item self-administered questionnaire, at their home or the program agency office. The survey instrument was expanded slightly and administered nine months later as a posttest. Program and comparison adolescents completed identical forms at pretest and posttest. Five percent completed their interview and questionnaire in Spanish; these adolescents did not differ on any indicator from those who responded in English. Although program clients were not paid for taking part in the evaluation, comparison youths received a $5 gift certificate for filling out the pretest questionnaire and a $10 gift certificate for completing the posttest form. All respondents (and their parents or guardians) provided written informed consent to participate.