Order of online listings of medical symptoms influences how people perceive health risks

University of WarwickMar 15 2012

New research finds that the order of online listings of medical symptoms influences how people perceive their health risks.

Dr Chris Olivola, Research Fellow in the Behavioural Science Group at Warwick Business School, University of Warwick, is joint author of a research report to be presented in the next issue of Psychological Science, the journal of the Association for Psychological Science - http://www.psychologicalscience.org/ .

The study aimed to examine if individual's self-diagnosis and risk perceptions after browsing online symptoms would vary according to how these medical symptoms were displayed. The results reveal that how information is presented online will make a substantive difference in people's perceived risk of having a disease.

The research took the form of two tests, one on a fictional form of cancer (to ensure no participants could make use of prior knowledge), and one on a real type of brain cancer. The symptoms were presented to groups of participants in three different formats:

as 3 general (eg feeling tired easily) followedby 3 specific (eg a lump in the neck)-
as 3 specific then 3 general symptoms,-
as an interspersed mix of both.

Study participants who viewed specific symptoms listed together, and general symptoms listed together (in either order) perceived their medical risk to be significantly higher than those who were shown the very same symptoms presented in alternating order (the interspersed version).

The second study on a real type of brain cancer also varied whether the number of symptoms listed was six (as in the first study) or 12. The researchers found that the effects of symptom presentation order were diluted when there were 12 symptoms, indicating that the length of the list of symptoms can also influence decisions.

Dr Olivola commented, "As more and more people can and do access medical info online, these results have serious implications for patients and healthcare providers. This is particularly true of the NHS, which could be further overstressed if common symptoms are listed together, leading people to increase their perceived risk of having a disease and therefore increasing visits to their medical doctors. Healthcare organisations need to pay attention to the way they present the symptoms associated with diseases and other health risks."