Improving Understanding of Health-Relevant Numerical Information

In this chapter, we discuss why risks are often not communicated in a transparent and understandable way and why this is problematic. At the core of the chapter are four examples that illustrate how risk communication can be improved. These examples are (a) the use of natural frequencies in the context of diagnostic reasoning, (b) the use of visual aids to support the beneficial effect of natural frequency representations, (c) the use of natural frequencies to clarify the distinction between relative and absolute risk reduction, and (d) a clarification of the meaning and pitfalls of survival rates that are often used to quantify the benefit of screening programs. In each of these topics, we describe original empirical studies illuminating a specific problem as well as how these problems can be overcome, and we discuss practical implications of the results and the proposed solutions. Subsequently, we illustrate, using an example from mammography screening, what transparent risk communication could look like. The chapter concludes with a discussion of training programs designed to enhance health-related, high-stakes decision making.