Women's perception of the benefit of breast cancer screening.

Harms? False positives with biopsiesb 50–200 Unnecessary treatmentsb 2–10 Doctors, health pamphlets from national cancer societies, and he Internet all inform women about early detection of breast caner and the benefits of mammography screening. Thus, women hould be fairly knowledgeable about screening. Yet nothing is farher from the truth, as documented by the first European-wide tudy [1] that included a representative sample of about 5000 omen from Austria, France, Germany, Italy, Spain, Poland, the nited Kingdom, and Russia (European part). Ninety-two percent fwomenoverestimated the benefit of screening tenfold, hundredold, two-hundredfold, or did not know; in France, Germany, and he Netherlands, the percentage rose to 98%. Why are women so ighly misinformed in Europe? In defence of Russian women, one ight note that mammography screening is rare in Russia. Yet the ussian women made by far the most realistic estimates—likely rom receiving not more but less misleading information. What exactly are women told about the benefits of breast caner screening? Many doctors convey an emotional message: that arly detection is a moral responsibility, that women should think f their families and take care of their bodies. Pamphlets emphasize hat screening can save lives but rarely provide numbers, which are ore likely to be found onWeb sites. If numbers about benefits are iven, then most pamphlets and Web sites frame information in a ormat that misleads women, such as relative risk reductions [2]. omen are told that screeningwithmammography reduces breast ancer mortality by 20% or even 25%. Elsewhere they are told that he 5-year survival rate for women who participate is 98%. This is here Jane Q Public begins to get confused: Does that mean that at east 20 out of every 100 women—or even 98%—who participate in creening are saved? Such confusion ariseswhen interested parties ry to exaggerate benefits and to withhold information about the isks in order to increase participation rates. The 20% and 98% figres aim at persuasion, not information. What, in contrast, would ransparent information look like? The fact box in Table 1 is such a transparent, simple, and quick ool. The two relevant questions it asks are:What are the benefits? hat are the harms? The columns present the two alternatives, articipating in screening or not, which makes it easy to compare he consequences of each side-by-side. Most important, the inforation is given in transparent numbers (e.g., out of 1000), not in erms of misleading relative risks or survival rates. Such fact boxes avebeen shownto fosterunderstanding forbothbenefits and risks n the general public [3]. A 50-year-old woman who wants to decide whether or not to articipate in screening can find the major benefits and harms in he fact box. There are two ways she can think of the benefit of creening. First, does it decrease her chances of dying from cancer,