Communicating Down syndrome risk according to maternal age: "1‐in‐X" effect on perceived risk. (9th June 2015)

• Record Type: Journal Article
• Authors: Pighin, Stefania; Savadori, Lucia; Barilli, Elisa; Galbiati, Silvia; Smid, Maddalene; Ferrari, Maurizio; Cremonesi, Laura
• Is Part Of: Prenatal diagnosis. Volume 35:Number 8(2015:Aug.)
• Page Start: 777
• Page End: 782
• Publication Date: 2015-06-09
• Subjects: Prenatal diagnosis -- Periodicals; Fetus -- Diseases -- Diagnosis -- Periodicals; Electronic journals; 618.32075
• DOI: 10.1002/pd.4606
• Languages: English
• ISSNs: 0197-3851

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <sec id="pd4606-sec-0001" sec-type="section"> <title>Objective</title> <p>The appropriateness of the 1‐in‐<italic>X</italic> numerical format to convey quantitative medical probabilities is currently under discussion because of its distortive effect on subjective probability assessment. Previous research, however, always asked participants to imagine a hypothetical scenario. The aim of the present research is to support the existence of the 1‐in‐<italic>X</italic> effect in a real setting: when pregnant women have to evaluate their personal risk of Down syndrome according to their maternal age.</p> </sec> <sec id="pd4606-sec-0002" sec-type="section"> <title>Method</title> <p>During the first prenatal visit, pregnant women were asked to evaluate their own risk of having a child with Down syndrome according to their age, when such risk was presented either in the 1‐in‐<italic>X</italic> or in the <italic>N</italic>‐in‐<italic>NX</italic> format. Then, they were asked to assess their risk of having a child with Down syndrome.</p> </sec> <sec id="pd4606-sec-0003" sec-type="section"> <title>Results</title> <p>Results showed a systematic higher risk assessment when pregnant women were presented with the 1‐in‐<italic>X</italic> format (mean = 3.57, standard deviation = 1.4) than with the <italic>N</italic>‐in‐<italic>NX</italic> format (mean = 3.03, standard deviation = 1.4), <italic>P</italic> = 0.007. Whereas the effect was shown to be not moderated by a differential comprehension of the two numerical formats, women with a low educational level and those who were at their first pregnancy were shown to be significantly more vulnerable.</p> </sec> <sec id="pd4606-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The present findings corroborate the existence of the 1‐in‐<italic>X</italic> effect in a real‐world setting, showing that, in pregnant women, the 1‐in‐<italic>X</italic> format actually elicits a higher perceived risk of Down syndrome, compared with the <italic>N</italic>‐in‐<italic>NX</italic> format. © 2015 John Wiley & Sons, Ltd.</p> </sec> </abstract>