Most people understand that statistical analysis is used to summarize a set of data, identify trends, and confidently project the probability-or risk-of a particular event or outcome. But how relevant are statistics to our individual experience? Are we at serious risk of contracting Disease X or developing Condition Y? How much should we worry about these risks in the context of our everyday lives? Our inherent desire to understand the myriad risks to our health drives many of the everyday decisions we make, from lifestyle choices to consumer patterns to political views. But much of the information we receive about risk is derived from the painstaking mathematical analysis of large and complex sets of information, which requires an expertise that is well beyond the grasp of most people.

Yet non-statisticians can take heart. While there is much more to statistics and risk than meets the eye, we can easily extract meaningful information from a set of data by asking the right questions. Once we gain an appreciation of how risk information can be interpreted-and misinterpreted-we can begin to make informed decisions about our own health and that of our society.