Tuesday, October 16, 2012

What the Contraceptive Choice Study Really Shows [Serge]

Update: Lydia McGrew has a more extensive and detailed analysis of this paper over at What's Wrong with the World.

News reports for the last couple weeks have been glowing about a new study that purports to lower abortion rates by offering contraception for free.  "Free contraception cuts abortion rates dramatically" is an example from NBC news.  This sounds promising, but as usual a closer look at this study tells a very different story.

The study itself is part of the Contraceptive Choice Project in St. Louis.  The preliminary results of the study can be found here, and a pdf presentation from the study's main author can be found here.  The claim is that this study has shown that increasing access to contraceptives by making them free shows a general decrease in the unplanned pregnancy and the abortion rates.   There are a number of reasons to indicate that the study does very little to support that claim.

First, it is important to look at the goals of the study.  According to the author the goal were "(1) To increase the acceptance and use of long-term reversible contraceptive (LARC) methods among women of childbearing age  and (2) To measure acceptability, satisfaction, side-effects, and rates of continuation across a variety of contraceptive methods, including long-term reversible methods."  It was not an attempt to study whether increased access to traditional contraceptives would increase their use and effectiveness, but an attempt to convince women to change the type of contraception that was used.  This is very important, and almost never mentioned in the news reports.

Second, the study group itself is very interesting.  Dr. Michael New has mentioned that there was no control group to compare the study group to.  However, even more important is the characteristics of the group itself.  Women who volunteered for the project were recruited mainly from Washington University and various abortion and family planning clinics.  In order to be involved in the program, the women had to be desiring contraception and be willing to change the type of contraception that they were presently using (if any).  66% of the women in the program had previously experienced an unintended pregnancy, and 40% of them had a previous abortion.  39% of the women had a history of an STD, and 6% presently had an STD.

Is it possible that this group, who were already seeking contraception and most have experienced an unintended pregnancy, may be more willing and motivated to change their contraceptive method for this study?  Data extrapolated from this group of women cannot be accurately applied to the public at large, yet that is exactly what the news media would have us believe.

Lastly, the goal of the study was to convince women to forgo traditional methods of contraception (mainly OCs) in favor of more effective, long-term methods.  These LARC methods were IUDs or implantable hormonal contraceptives.  Over 75% of the women in the study were convinced to change from traditional methods to longer acting methods, and this accounts for the majority of the success in preventing unplanned pregnancies.   The challenge that the researchers had, and one that they were highly successful in this group, was to convince women to change from a non-invasive method of contraception to an invasive one.  There is no reason to believe that women in the general public, and especially teens, would be willing to choose these more invasive methods over regular OCs.  Convincing a 15 year old that is looking for a pill to have a 4cm implant placed in her or have this contraption placed in her young uterus will not be easy.


Anyone who doesn't think this won't be a significant barrier hasn't been paying attention to the other side.  For years, family planning clinics have been looking to stop requiring pelvic exams for women who are seeking contraception.


Indeed, according to a consortium of health-care providers and researchers, called Oral Contraceptives Over-the-Counter Working Group (OC-OTC), the annual pelvic exam is still a major barrier to access to contraception for many American women.
So lets get this straight.  Having a doctor perform a pelvic examination (for the benefit of the woman) is a major barrier to contraception.  Yet this study would have us believe that upwards of 75% of women would allow not only examine her "ladyparts" (with apologies to the Obama campaign), but allow the placement of a hormonally saturated contraption in her uterus, knowing that it would also have to be removed by a doctor at a future date when a pregnancy is wanted.  Good luck with that.
Bottom line: in a carefully chosen group of women, who may be highly motivated to change their contraceptive methods and avoid another pregnancy, LARCs may help them avoid pregnancy.  However, extrapolating that data to apply to the public at large, and especially including tradition types of contraception is not supported.  This study reveals nothing to believe otherwise.

4 comments:

  1. Excellent, Serge, thanks! I think it's especially telling that they give as a criterion of inclusion in the study that the women must be willing to "change their method" of family planning! That's pretty huge as far as the question of representative sample. Obviously not all women in general, even those who presently use contraception, are willing to change their method! It appears that they allowed them to change their method to pills or rings, but this might have been a change from, say, condoms or some other barrier or spermicidal method. Women who were satisfied with this method or who wanted to "take their chances" on getting pregnant were, of course, not included in the study.

    I have another question: Michael J. New states that the abortion rates were not per se taken from actual study participants. He seems to be implying that they were estimated in some fashion and that some of the reduction in abortions may therefore have come from non-participants.

    I've looked quickly over both the Powerpoint and the summary, and neither of them addresses the question of how they got their abortion statistics. Naturally, one would assume that when they say something about the abortion rate among participants, they are actually talking about abortions among participants! So New's claim is a pretty big deal. But I can't figure out where he's getting it from. I wrote an e-mail to the NRO site but haven't gotten a reply yet.

    Do you have any clue to why he is saying that the abortions among participants were not actually just counting participants?

    ReplyDelete
  2. I believe it was in the way the data was standardized. To be honest, I was confused by the original paper, which I was able to track down today. I'll provide a long quote from the part where they speak how they estimated the abortion rates. I can get the pdf of the original article to you if you wish - pm me on facebook.

    "Although not an a priori primary outcome of interest, we also estimated abortion rates because the majority of abortions result from unintended pregnancies...

    "Abortion rates among participants aged 15–44 years and births among participants aged 15–19 years within CHOICE were compared with regional and national rates. Because the CHOICE cohort represents a higher-risk population (median age of 25 years and 50% black) than the general population, we standardized the CHOICE abortion rate to the age and racial (black and white) distribution of females who reside in the St. Louis region using data from the 2010 U.S. Census (direct standardization). We compared the CHOICE standardized rate with the St. Louis regional
    rate using data from the Missouri Department of Health and Senior Services and with the national rate
    using the most recent published data from 2008."

    ReplyDelete
  3. That is pretty confusing, but it definitely says "estimated," which lends support to what New says.

    ReplyDelete
  4. My companion piece to yours is up. http://www.whatswrongwiththeworld.net/2012/10/preliminary_thoughts_on_the_co.html

    ReplyDelete

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