Purpose: Infectious disease outbreaks are uncertain and risky events that often attract considerable media attention. Regardless of objective severity, diseases with high media frequency (HMF) are considered to be more serious, and more representative of a disease, than those with low media frequency (LMF)1. We assessed the role of the media in perceptions of population risk (perceived population prevalence), and perceptions of personal risk (perceived personal likelihood of infection) for infectious diseases that are either frequently or infrequently mentioned in the public media.
Method: Undergraduate students (n=23) were asked to evaluate 34 medical conditions in a paper-based task, 10 of which were the focus of this study. Five disease ‘pairs’ were created matching for similar vectors of transmission, symptoms, prevalence, but differing on media frequency (e.g. high, such as anthrax, vs. low, such as tularemia). Participants rated each disorder in terms of seriousness (10-point scale), representativeness (4-point scale), population prevalence (of 1,000 of their peers), and personal risk (10-point scale).
Result: Participants rated the HMF diseases as more serious (mean = 7.15 compared to 6.0; F(1,21) = 23.06, p < .001), more representative (3.12 compared to 2.74; F(1,21) = 26.41, p < .001) , and rarer (28.9 compared to 105.4; F(1,21) = 70.29, p < .001), than paired LMF diseases. Participants did not rate HMF and LMF conditions differently in terms of personal risk. Coordination between perceptions of personal and public risk was higher for LMF conditions (r = .63), than HMF diseases (r = .42), indicating a disconnect between personal and public risk perception for HMF diseases. On closer examination of the relation between public and personal risk perception for HMF diseases, a logarithmic function explained more variance (r = .59, p < 0.001), and performed better than the linear regression (r = .33, p < 0.001), indicating an overestimation of personal risk compared to population risk.
Conclusion: We found that illnesses with a high media presence are perceived to be more serious and more representative of disease. We also observed dissociation between ratings of personal and public risk. It appears that this dissociation is not being driven by unrealistic optimism, but rather an exaggeration of personal risk compared to overall population estimates (unrealistic pessimism), presumably driven by increased media frequency. 1 Young et al.(2008). PLoS–ONE,3(10),e3552.
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