Reducing adolescent pregnancy through a school- and community-based intervention: Denmark, South Carolina, revisited

Family Planning Perspectives, Sep 1994 by Koo, Helen P, Dunteman, George H, George, Cindee, Green, Yvonne, Vincent, Murray

The publication of a 1987 article in the Journal of the American Medical Association evaluating a pregnancy prevention program in Denmark, S.C., showed declines in estimated pregnancy rates among adolescents in the intervention area. A reanalysis of the data that selected better matched comparison areas and extended the time period covered confirms that the adolescent pregnancy rate in the intervention area significantly deceased from an annual average of 77 pregnancies per 1,000 women aged 14-17 during the preprogram period (1981-1982) to 37 per 1,000 following the intervention (1984-1986). However, the reanalysis also shows that the pregnancy rate returned to a higher level (66 per 1,000) in 1987-1988 after the discontinuation of important program components and related nonprogram services. These services included the efforts of a school nurse, who provided contraceptive services to students and whose intervention was not previously reported. (Family Planning Perspectives, 26:206-211 & 217, 1994)

In a 1987 article, Vincent, Clearie and Schluchter reported the success of a program designed to reduce pregnancy rates among adolescent girls.(1) This program, the School/Community Program for Sexual Risk Reduction Among Teens, was initiated in the early 1980s in the South Carolina community of Denmark, located in Bamberg County. The program used an intensive school- and community-based educational approach that included graduate-level sexuality education courses for school teachers; workshops for parents, clergy and community leaders; programs that trained students to serve as peer counselors; and media campaigns. According to the article, the Denmark program prompted a sharp decline in estimated pregnancy rates in 1984 and 1985 among young women aged 14-17 in the program area, which encompassed about half of Bamberg County. During the same period, adolescent pregnancy rates rose in three comparison counties that did not receive program services. In a fourth comparison area (the nonintervention portion of Bamberg County), however, the adolescent pregnancy rate did decline. Vincent, Clearie and Schluchter attributed this result to the informal dissemination of the Denmark program's messages to the neighboring area.

The 1987 article, along with the editorial that accompanied it, generated considerable national publicity and led to efforts by other communities to replicate the Denmark program. Because of this intense interest, we decided to reexamine the decline in pregnancy rates in the Denmark area. We also decided to investigate all plausible alternative explanations for the decrease because communities interested in replicating the Denmark program would need to know whether factors other than the program components originally described also played a role in bringing down adolescent pregnancy rates.

Our research into other possible causes found that concurrently with the operation of the Denmark program, a school nurse counseled students who were at risk of initiating sexual intercourse to avoid doing so and provided students who were already sexually active (or who would not follow her advice to delay sexual intercourse) with contraceptive counseling, services and supplies. She gave condoms to adolescent men and took adolescent women to the county health department family planning clinic to receive birth control services and supplies. In the analyses reported below, we consider both the Denmark program and the activities of the school nurse as parts of the total intervention for preventing adolescent pregnancies in the Denmark area.

Data and Methods

We used three strategies in the reanalysis. First, we expanded the criteria for selecting the comparison counties so that those counties would be more closely matched to the intervention area. We also extended the period studied to permit examination of adolescent pregnancy rates in the intervention and comparison areas for longer time spans both before and after the program began. Third, we recalculated pregnancy rates after adding live births and induced abortions among 18-year-olds who probably conceived when they were 17. These pregnancies were not included in the pregnancy rates calculated in the original study.

New Comparison Counties

In the original analysis, three comparison counties were selected on the basis of their similarity to Bamberg County on five socioeconomic variables: population size, population density, the percentage of population that was nonwhite, per capita income and percentage of adults who did not complete high school. The selection criteria should also have included preintervention pregnancy rates among adolescents as an essential matching variable. Because two of the three comparison counties had preprogram pregnancy rates significantly lower than the rate in Bamberg County, their pregnancy rates had a higher probability of increasing over time. As a result, the reported difference between the change in the Denmark rate and the rate changes in the comparison counties--which was attributed to the effectiveness of the Denmark program--was a biased estimate.