Some ideas on communicating risks to the general public

Relative risk statements speak of risk increasing or decreasing by a percentage, for instance, that mammography in women over 40 reduces the risk of breast cancer by 25%. But all percentages erase the frequencies from which they were derived. We cannot tell from the relative risk reduction what is the absolute risk reduction: by how much does the risk of breast cancer actually decrease between those who get mammographies and those who do not: the answer is .1%

Relative risk information does not give information on how many people need to undergo a treatment before a certain benefit is obtained. In particular, based on the relative risk information, can one say how many women must be screened before a single life is saved? If your intuition tells you 4, you are again far off, as 1000 women must be screened to save the one life. In this way, relative risk information can cause people to misjudge the effectiveness of treatments