Risk
In healthcare studies, the risk means the probability of a bad outcome such as illness or death. There are two kinds of risk that are easy to confuse: absolute risk and relative risk. Absolute risk means the chances of developing a disease or other condition within a certain time period. For example, currently, a woman's lifetime absolute risk of breast cancer is one in nine; that is, one out of nine women will develop breast cancer at some point during their lives. This can also be expressed as a percentage; e.g., 11%. Relative risk is used to compare risk in two different groups of people. For example, studies have shown that women who drink alcohol have a higher risk of developing breast cancer than non-drinkers. If, for example, the drinkers had a 16.5% chance of developing breast cancer, then their relative risk would be 50% higher. This is an area that causes a lot of confusion for the media and consumers of health and medical news, because it is easy to become alarmed when we read figures such as "50% higher risk." It is very important to remember that in both groups -- women who drink and woman who do not -- the breast cancer risk is under 20%; "50% higher risk" does not mean that women who drink are at anywhere near a 50% absolute risk of developing breast cancer.