[Information on mammography screening--from deception to insight].

Information about mammography-screening as a basis for informed-decision making has to be evidence-based and presented in an unbiased format. This includes communication of results about effectiveness/lack of effectiveness of screening programmes (breast cancer mortality, total mortality), the quality of mammography as a screening test (sensitivity, specificity, positive and negative predictive values), and possible harm (consequences of false positive and false negative results, overdiagnosis of breast cancer, overtreatment). Outcome data have to be communicated as natural frequencies rather than relative differences. In order to avoid framing of data equal emphasis has to be put on the proportion of persons who are likely to benefit and those who are unlikely to benefit or likely to be harmed.