I read the news today. Oh boy!here you are, after all!) to stay current with research in the field. Sure, we'd all like to sit down and actually read the latest journals, but there are patients to see, calls to return, vacations to plan, and lawns to mow.
Usually these convenient information sources are reliable, up-to-date, and clear. Sometimes, though, they inadvertently remind us of the need to read carefully and to go back to what our social studies teachers once called “primary sources” before we draw conclusions.
One of my favorite medical e-newsletters is Medscape's Ob/Gyn Women's Health Medscape CME Pulse, the most recent of which reached my inbox on Sunday. The e-mail, which also featured articles on gestational diabetes and weight gain prevention, had a headline that grabbed my eye: “Hormonal Contraceptives May Not Be as Effective in Overweight or Obese Women.”
That would be epic news. As the article itself says, “Obesity has reached epidemic proportions around the world.” We all have overweight and obese patients in our practices, and those of us who prescribe birth control would face major issues if contraceptive efficacy were compromised for these young women.
Naturally I clicked on the headline to follow a link to an online article, which turned out to be reporting on a Cochrane Report study on weight/BMI and birth control efficacy. The study aggregated findings from 11 studies dealing with weight or BMI; the primary outcome was pregnancy. The authors wrote: “Only one of three studies using BMI found a higher pregnancy risk for overweight women. The efficacy of implants and injectable contraceptives may be unaffected by body mass.” One of the reported findings was a higher failure rate for the birth control patch among women who weigh more than 70 kg (198 lbs), but that's old news, well-known in the women's health community.
Now, the headline did hedge its announcement by saying that hormonal contraceptives may not be as effective in overweight or obese women -- but what these findings suggest to me is that hormonal contraceptives may be as effective in overweight or obese women. But that's a less exciting headline, right? I know I would be much less inclined to click on a link reiterating things I already believe to be true.
Just to clear the air, let's drop the electronic cynicism for a moment and crunch the data. Read the Cochrane Report yourself. Look at the most current expert guidelines: According to the CDC's newly-released medical eligibility criteria for contraception in the U.S., obese women can use any contraceptive method except combined hormonal contraceptives (the Pill, patch, or ring) with no restriction after age 18. Even for combined hormonal contraceptives, the benefits of the method generally outweigh the risks (i.e., DVT). Women under age 18 should use caution when choosing the contraceptive injection because of the risks of increased weight gain associated with that method.
As the Cochrane study authors agree, more research is needed into the relationship between BMI/weight and birth control efficacy. No one would dispute this. But for now, let's all agree to exercise caution in drawing our conclusions. And in writing our headlines. Readers, take this as a reminder to read carefully and follow links.