OBJECTIVE. The US government spends more than $200 million annually on abstinence-promotion programs, including virginity pledges. This study compares the sexual activity of adolescent virginity pledgers with matched nonpledgers by using more robust methods than past research.
SUBJECTS AND METHODS. The subjects for this study were National Longitudinal Study of Adolescent Health respondents, a nationally representative sample of middle and high school students who, when surveyed in 1995, had never had sex or taken a virginity pledge and who were >15 years of age (n = 3440). Adolescents who reported taking a virginity pledge on the 1996 survey (n = 289) were matched with nonpledgers (n = 645) by using exact and nearest-neighbor matching within propensity score calipers on factors including prepledge religiosity and attitudes toward sex and birth control. Pledgers and matched nonpledgers were compared 5 years after the pledge on self-reported sexual behaviors and positive test results for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis, and safe sex outside of marriage by use of birth control and condoms in the past year and at last sex.
RESULTS. Five years after the pledge, 82% of pledgers denied having ever pledged. Pledgers and matched nonpledgers did not differ in premarital sex, sexually transmitted diseases, and anal and oral sex variables. Pledgers had 0.1 fewer past-year partners but did not differ in lifetime sexual partners and age of first sex. Fewer pledgers than matched nonpledgers used birth control and condoms in the past year and birth control at last sex.
CONCLUSIONS. The sexual behavior of virginity pledgers does not differ from that of closely matched nonpledgers, and pledgers are less likely to protect themselves from pregnancy and disease before marriage. Virginity pledges may not affect sexual behavior but may decrease the likelihood of taking precautions during sex. Clinicians should provide birth control information to all adolescents, especially virginity pledgers.
Comments
Not surprising
To the Editor.
Rosenbaum's study(1) addressed an issue that is important with respect to both teenage health and efficient spending of tax payers' money. Her findings are not surprising; they indorse what we feel we have known about human nature all the time, and they are in line with other research into the effectiveness of abstinence programs(2). Now the question is: will the waste of federal money on risk-increasing programs be stopped or will dogma prevail over science?
1 Rosenbaum JE. Patient teenagers? A comparison of the sexual behavior of virginity pledgers and matched nonpledgers. Pediatrics. 2009;123:e110-e120.
2 Underhill K, Montgomery P, Operario D. Sexual abstinence only programmes to prevent HIV infection in high income countries: systematic review. Br Med J. 2007;335:248.
Conflict of Interest:
None declared
Drawing policy conclusions from virginity pledge results
This paper presents a welcome application of matching estimators in an attempt to isolate any causal impact of virginity pledges on sexual behaviour and outcomes. The author finds that pledgers are significantly less likely to use condoms than nonpledgers but that there is no statistically significant difference on most measures of sexual activity and sexually transmitted infections. These are interesting findings. However, a closer look at the results in the paper makes it clear that they do not fully support the conclusion that funds should consequently be shifted away from abstinence programs.
The point estimates reported in Table 2 of the paper are striking in that pledgers appear to have fewer partners, lower rates of sexual activity and lower rates of sexually transmitted infections than similar nonpledgers. Further, the effects implied by the point estimates are quite large in magnitude. For example, pledgers have a rate of chlamydia infection that is 43% lower than amongst similar nonpledgers. The high standard errors, however, mean that virtually none of these effects are statistically significant at conventional levels. We need to be clear about the inference we can draw from this. These results do not provide evidence that virginity pledges do not change sexual behavior. Rather, the results do not provide sufficient evidence to enable us to be sure that the observed differences in sexual behavior are not due to chance.
Whether or not the strong policy conclusions drawn from these results are appropriate depends crucially on the power of the tests. On this we are not given sufficient information to form a judgement, but the fact that a 43% reduction in chlamydia infection amongst pledgers is not picked up as statistically significant suggests that at least some of the tests are of fairly low power. i.e. even if pledges do have beneficial impacts on sexual activity or sexually transmitted infections, the tests in the paper are unlikely to reveal these impacts as being statistically significant.
So how should we respond to the results in this paper? In the first place, the results demonstrate the need for further research on the impact of these programs using a methodology which is sufficiently powered to be able to pick up impacts of moderate size. It seems particularly injudicious to call for the withdrawal of funding from of abstinence programs. After all, if the large reduction in chlamydia infection amongst pledgers turns out not to be due to chance, then the withdrawal of funding from such programs could have very damaging impacts on adolescent sexual health.
Second, the result in the paper that pledgers use condoms significantly less than nonpledgers less but (even at worst) they do not have higher rates of STIs presents a serious challenge to those who are devising policy based on the assumption that greater condom use will lead to lower rates of STIs amongst adolescents. It is clear that further research on this question is urgently needed.
Taken as a whole, the results in this paper should provide some encouragement for proponents of abstinence education in that virginity pledges do not appear to have any adverse consequences on the level of sexual activity or on sexual health and may have some beneficial impacts. Further encouragement comes from recent research based on similar methodology but focusing on outcomes amongst on younger adolescents and which found virginity pledges significantly delay sexual intercourse initiation without affecting condom use (1). Whether or not the possible beneficial impacts of pledging on sexually transmitted infections suggested by this paper can be substantiated by a more powerful research design remains to be seen.
REFERENCES
(1) Martino SC, Elliott, MN, Collins, RL, Kanouse, DE and Berry, SH. Virginity pledges among the willing: delays in first intercourse and consistency of condom use. Journal of Adolescent Health 2008: 43; 341-8.
Conflict of Interest:
None declared
Religiosity, Not Pledging, Makes the Difference
The most interesting finding of this research is not the data with respect to pledging vs non-pledging, but the differences in sexual behavior based on religiosity, or overall religious activity, of adolescents. The religious teens were found to delay sex an average of three (3) years relative to non-religious. This is significant if we want to reduce teen preganacy and STDs. Pledges are often taken in emotional rallies, and teens sign on the emotion of the moment. This is not likely to hold up in the heat of sexual passion later on. Teens will "forget about" their pledges. However, teens more deeply socialized within a religious environment growing up, and with the ongoing support of a religious community, and with continued peer religious activity, may be more likely to delay sexual activity and avoid related problems. This is the most important interpretation I have of this study.
Conflict of Interest:
None declared