How can we better communicate numbers and probabilities in medicine?

In medicine, healthcare professionals are often faced with the task of communicating risks. How likely is it that a treatment will be effective? How often do complications happen during a procedure? How frequently do certain side effects occur? Such numerical information is an essential part of providing patients with thorough information. However, depending on how the doctor or therapist explains these figures, patients may react to them very differently.

For example, the statement “The probability of surviving this surgery is 99 percent” sounds significantly less alarming to most people than the mathematically equivalent phrasing: “The probability of dying during this surgery is one percent.” This is due to what is known as “framing”: The first sentence emphasizes the high probability that everything will turn out well – this is called positive framing. The second sentence, on the other hand, draws attention to the risk of dying during the surgery – and although this risk is small, such negative framing can trigger or intensify fears.

Does “1 in 100” sound the same as “1 percent”?

This is where the affiliated project AF05 comes in: It investigates how different ways that a doctor frames the risk of a serious illness affect the behavior of volunteers. To do this, the researchers are first measuring the extent of the influence of positive and negative framing during a discussion of medical findings.

Second, they examine the extent to which participants interpret frequencies (“1 in 100”) and percentages (“1%”) differently. In addition to personal risk assessment, the study also examines how strongly participants feel the need for further medical tests and whether they would like to seek a second medical opinion.

Effective communication of numbers can make a big difference – without costing any additional time or money.

With this approach, the AF05 project is highly relevant to everyday medical practice – and does so without incurring additional costs. This is because the results can be used to derive concrete recommendations on how healthcare providers can communicate medical findings in a way that ensures their patients are optimally informed without being unnecessarily unsettled. The same applies to consultations explaining the benefits of a treatment and discussing potential risks and side effects: Here, deliberate framing and careful word choice can minimize nocebo effects. This, in turn, has a positive impact on patients’ willingness to stick with an appropriate treatment. At the same time, it increases the likelihood that the treatment will be successful.