Risk perception is affected by modes of risk presentation among Singaporeans.

INTRODUCTION Not much is known about how Singaporeans perceive and react to risk presentation. There is no consensus on whether the European Union guidelines for describing the risk of side effects are valid. This study investigated the effect of different modes of risk presentation on how Singaporeans perceive and react to medical risk. Furthermore, we investigated the practical usage of qualitative phrases, the European Union's adjectives in particular, in describing levels of risk. MATERIALS AND METHODS A hypothetical situation about the risk of side effects of an influenza vaccine was presented in either a probability format (i.e., 5%; n = 42) or a frequency format (i.e., 1 out of 20; n = 43). The 2 versions of questionnaire were handed out in an alternate order to a convenience sample of 47 healthcare professionals and 38 university students. RESULTS Respondents presented with a "5% risk" were more likely to describe the risk as "uncommon" or "rare", as compared to respondents presented with a risk of "one out of twenty" (P <0.01). Furthermore, the former showed more willingness to accept the influenza vaccine described in the hypothetical situation than in the latter, but this was not statistically different (67% versus 54%; P >0.1). CONCLUSIONS Modes of risk presentation affect how people perceive risk, even among people who are highly educated.