A new study which recently appeared in the journal Obstetrics and Gynecology has the mainstream media swooning. A program which provided free contraception to over 9,000 women in the St. Louis area purportedly resulted in dramatic reductions in abortions, repeat abortions, and teen births. This study has been covered by USA Today, the Associated Press, CBS News and countless other media outlets.
Specifically, the researchers enrolled 9,256 adolescents and women in the program. Participants were recruited from the two abortion facilities in the St. Louis region and through provider referral, advertisements, and word of mouth. All participants received the reversible contraceptive method of their choice. However, the researchers highlight the fact that 75 percent of women taking part in the study chose a long-acting reversible contraceptive (LARC) — either an IUD or an implant. Many will doubtless use these findings to buttress their case for mandates on contraceptive coverage in insurance programs and greater government spending on contraceptives. However, there are at least five reasons why this study greatly overstates the impact of no-cost contraception.
1) No control group: The main problem with this study is that it fails to include an adequate control group. Each of the 9,256 participants in the study was a volunteer. As such, women in the study very likely had a stronger desire to avoid a future pregnancy than women who declined to participate. Most research indicates that a desire to avoid pregnancy has a significant impact on the likelihood of becoming pregnant. As such, comparing the abortion rate and the birth rate of study participants to national and state averages is a flawed comparison. A better idea would have been to randomly select some percentage of the volunteers, inform them that they were not going to receive free contraception, but continue to track their births and abortions in exchange for some compensation. That would have allowed for a meaningful comparison between a treatment group and a control group.
2). Limited impact on repeat abortion rate: The study makes much of the fact that between 2006 and 2010 there was a statistically significant decline in the repeat abortion rate in St. Louis City and County. This may well be true. However, the results indicate that the repeat abortion rate fell from about 48 percent in 2006 to about 45 percent in 2010 — hardly a dramatic decline.
3) Exaggerated impact on overall abortion rate: The authors also make much of the fact that the number of abortions performed at Reproductive Health Services on women who resided in St. Louis City and County declined by 20.6 percent between 2008 and 2010. However, Reproductive Health Services is not the only abortion provider in the St. Louis area. Furthermore, only a small percentage of St. Louis area women took part in the program. Now, the authors use a weighting method and, as such, do not provide the actual number of abortions performed on program participants. However, my back-of-the-envelope calculations indicate that much of this abortion decline was among women not taking part in this no-cost contraceptive program.
4) The weighting mechanism overstates effectiveness of contraception program: Program participants were not a random sample of women residing in the St. Louis area. They were more likely to be African-American, young, and low-income. As such, the authors weigh the data to compare birth rates and abortion rates of program participants to birth rates and abortion rates of a similar demographic cohort. Consequently, these contraceptive methods likely appeared more effective than they actually were — because they were being used by a demographic with both relatively high birth rates and abortion rates.
Now, sometimes weighting data makes sense. Some demographic groups have a higher incidence of sexual activity and use contraceptives less consistently. However, since a high percentage of study participants used long-acting contraceptive methods, weighting makes less sense. Long-acting contraceptive methods work automatically and their effectiveness should be less sensitive to the frequency of sexual activity. In the spirit of full disclosure, the authors should publicly provide the raw, unweighted data on the birthrate and abortion rate of study participants. That would provide a much better measure of the effectiveness of this program.
5) The results are not generalizable to a large population: The authors state that IUDs are more popular in Europe than they are in the United States. There are a variety of reasons for this. However, one factor the authors overlook is that many physicians in the United States are unwilling to insert IUDs because of liability issues. Indeed, IUDs users have an increased risk of pelvic inflammatory disease and perforation of the uterus. Also, if a woman using an IUD wants to get pregnant, her IUD would have to be removed by a physician. For this reason, even if these long-term methods were available at no cost, it is not clear that many women would choose to use them.
Interestingly, the study only tracked the abortion rates and birth rates among program participants. There was no effort to analyze how the provision of no-cost contraception impacted sexual activity, the incidence of sexually transmitted diseases, or any other public-health outcomes. If the authors are going to use this research to argue for mandatory coverage of long-acting contraceptives, they should continue to monitor and report on the health outcomes of study participants in the future. This is an important consideration, given that long-acting contraceptives pose some serious health risks.
All in all, the pro-life movement receives plenty of criticism from the mainstream media and supporters of legal abortion for not being more contraceptive-friendly. However, in reality there is little evidence that supports the effectiveness of contraceptive programs. Separate studies from both the Guttmacher Institute and the Centers for Disease Control both indicate that a low percentage of sexually active women forgo contraception due to high cost or lack of availability.
Additionally, there is a body of research documenting the ineffectiveness of various contraception programs. For instance, the Daily Mail reported that a program launched by the British government in 1999 to provide “comprehensive” sexual education and birth control to British teens resulted in consistent increases in the teen pregnancy rate. Similarly, a study of a free contraception program in Scotland which appeared in the journal Contraception in 2004 found no decline in abortion rates. Finally, a study of a free contraception program in San Francisco which appeared in the Journal of the American Medical Association found this program produced no decrease in unintended pregnancy rates. Of course, these studies typically receive scant attention from the mainstream media.