What's in a Name? A Pregnancy Scenario (Nov-07)

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Tell us how you'd respond to the results of a blood test for fetal chromosomal problems. And find out how your response compares with that of participants in a national survey.

Consider the following

Imagine that you are four months pregnant. You and your partner have talked with your doctor about prenatal screening tests for your fetus. Based on your family history and personal medical history, your doctor has told you that you're at low risk (2 in 1000) of having a fetus with chromosomal problems. Chromosomal problems include such conditions as Down Syndrome. In talking further with your doctor, you decide to have a routine blood test for chromosomal problems in your fetus. This test will help to give you a better estimate of the chance that your fetus would have a chromosomal problem.

Your doctor tells you that the results of this blood test have come back "abnormal." She clarifies that the blood test showed that your risk of fetal chromosomal problems is about 5 in 1000, which is higher than the number she had told you before the test. She next asks if you are interested in amniocentesis, a medical procedure in which a small amount of amniotic fluid is extracted from the amniotic sac surrounding the fetus. This procedure can tell you for sure whether or not the fetus has chromosomal problems. However, amniocentesis has its own risks. Your doctor explains that the risk of miscarriage as a result of amniocentesis may be as high as 5 in 1000.

In these circumstances would you be interested in having an amniocentesis performed?
  • Definitely No
  • Probably No
  • Probably Yes
  • Definitely Yes

How do your answers compare?

Many women decide to go ahead and have amniocentesis. There are two things in this scenario that could influence women's decisions about amniocentesis. First, the doctor described the test as "abnormal", a label that may increase worry about the possibility that the fetus would have a chromosomal problem. Second, the risk estimate of 5 in 1000 was higher than the original estimate of 2 in 1000, which also may increase concern.

CBDSM researchers, led by Brian Zikmund-Fisher, wanted to know how much influence labels such as "abnormal", "normal", "positive", or "negative" might have on people's decisions in situations like the one described above. To test this, they gave one group of women a scenario just like the one you read. In this scenario, the test results were described as either "abnormal" or "positive" before the risk estimate of 5 in 1000 was given. A second group of women read the same scenario, but in their scenario, the doctor presented only the numeric risk estimate, without any label.

Women whose test results were introduced using a qualitative label ("positive/abnormal") were significantly more worried - and significantly more likely to choose to have amniocentesis - than women who were told only the numeric risk estimate, without any label. Note that all of the women in this survey were told that they had the same final risk: 5 in 1000. The decision of the women in each group should have been the same, but adding that one qualitative label significantly changed what the women in the study decided to do.

Interestingly, the CBDSM researchers also found a reverse effect when test results were introduced with the labels "negative" or "normal." These labels tended to make women less worried and less likely to have amniocentesis than women in a comparison group. Again, these results show that adding a one-sentence introduction with a qualitative label could significantly change people's decisions.

Read the article:

Does labeling prenatal screening test results as negative or positive affect a woman's responses?
Zikmund-Fisher BJ, Fagerlin A, Keeton K, Ubel PA. American Journal of Obstetrics and Gynecology 2007;197(5):528.e1-528.e6.