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标题：Explaining Recent Declines in Adolescent Pregnancy in the United States: The Contribution of Abstinence and Improved Contraceptive Use
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作者：John S. Santelli ; Laura Duberstein Lindberg ; Lawrence B. Finer 等
期刊名称：American journal of public health
印刷版ISSN：0090-0036
出版年度：2007
卷号：97
期号：1
页码：150-156
DOI：10.2105/AJPH.2006.089169
语种：English
出版社：American Public Health Association
摘要：Objectives. We explored the relative contributions of declining sexual activity and improved contraceptive use to the recent decline in adolescent pregnancy rates in the United States. Methods. We used data from 1995 and 2002 for women 15 to 19 years of age to develop 2 indexes: the contraceptive risk index, summarizing the overall effectiveness of contraceptive use among sexually active adolescents (including nonuse), and the overall pregnancy risk index, calculated according to the contraceptive risk index score and the percentage of individuals reporting sexual activity. Results. The contraceptive risk index declined 34% overall and 46% among adolescents aged 15 to 17 years. Improvements in contraceptive use included increases in the use of condoms, birth control pills, withdrawal, and multiple methods and a decline in nonuse. The overall pregnancy risk index declined 38%, with 86% of the decline attributable to improved contraceptive use. Among adolescents aged 15 to 17 years, 77% of the decline in pregnancy risk was attributable to improved contraceptive use. Conclusions. The decline in US adolescent pregnancy rates appears to be following the patterns observed in other developed countries, where improved contraceptive use has been the primary determinant of declining rates. In recent years, the United States has had the highest rate of adolescent pregnancy of any of the world’s developed nations. 1 ^, 2 However, since 1991 these rates have declined dramatically. Pregnancy rates among 15- to 19-year-olds declined 27% from 1991 to 2000, 3 and birth rates (for which more recent published data are available) dropped 33% between 1991 and 2003. 4 The pattern of decline in US birth rates among adolescents is considerably different from the pattern in non–English-speaking European countries, where adolescent pregnancy rates peaked between 1965 and 1980 and then dropped dramatically. 1 Little of the decline in Europe seems attributable to delay in initiation of sexual intercourse, given that the median age at initiation has fallen since 1965, indicating that more teens were having sex. 1 ^, 5 In fact, the age at which young people initiate sexual activity has become increasingly similar across developed countries. 1 ^, 5 A mid-1990s analysis of 5 developed countries showed that adolescents in the United States initiated sexual activity at an age similar to that of adolescents in Sweden, France, Canada, and Great Britain but that they used contraceptives less frequently. 6 Reductions in adolescent pregnancy rates are the result of shifts in 2 key underlying behaviors: sexual activity and contraceptive use. Between 1971 and 1988, age at sexual initiation among US teenagers became increasingly younger, as demonstrated by increases in the proportion of adolescents who had ever experienced coitus. 7 ^– 9 At the beginning of the 1990s this trend reversed, and declines in early sexual experience have since been documented in both school-based and household surveys. 10 ^– 12 Social conservatives in the United States have ascribed much of the recent decline in adolescent pregnancy rates to increased abstinence from sexual intercourse. 13 Consequently, the US government now promotes abstinence until marriage (“abstinence only”) as its primary prevention message for teenagers. 14 Federal government requirements for abstinence-only programs specify that these programs must have as their “exclusive purpose” the promotion of abstinence outside of marriage and that they must not, in any way, advocate contraceptive use or discuss contraceptive methods other than to emphasize their failure rates. 15 Federal government funding for abstinence-only education in the United States has grown rapidly since 1998, despite a lack of scientific evidence in support of these programs and concerns about their informational content and ethical acceptability. 13 ^, 14 In addition, the federal government, through its foreign aid programs, has vigorously promoted abstinence as a means of preventing HIV infection among adolescents. 15 In a previous analysis, we examined nationally representative data derived from samples of US high-school students in an attempt to understand declining adolescent pregnancy rates. 16 We found significant increases in use of contraception among 15- to 17-year-olds between 1991 and 2001 and estimated that improved contraceptive use and delay in initiation of intercourse made equal contributions to declining pregnancy rates. In an effort to update that study, we conducted a more comprehensive analysis of the roles of increased contraceptive use and delayed initiation of sexual activity in explaining changes in pregnancy risk over the period 1995 to 2002 among young people aged 15 to 19 years. We used data from the 1995 and 2002 versions of the National Survey of Family Growth (NSFG), a nationally representative household survey that provides more complete coverage of female adolescents (particularly older adolescents and those who are out of school) than high-school surveys. The NSFG also provides detailed information about contraceptive use, allowing assessment of trends in dual- and multiple-method use, which can greatly reduce pregnancy risk.