Public (Mis)understanding of the UV Index.

The ultraviolet index (UVI) has been regularly reported in Australia for a decade but utilisation remains extremely low ( approximately 5%). Blunden, Lower, and Slevin, in a 2004 Journal of Health communication article, suggest that Australians' understanding of the UVI is "good," and education to increase awareness of the index is therefore no longer warranted. To test this position, focus groups were conducted followed by an intercept survey of 404 residents of Perth, Western Australia, aged 16-44 years, to explore understanding and familiarity with the UVI. Results suggested that far from being "good," the familiarity and understanding of the UVI of at least half of Australians is poor. This was exemplified by the following: mean estimations of average UVI values in summer and winter being highly exaggerated (19.8 and 11.8, respectively); 61.2% not appreciating that the UVI is independent of temperature; at least 55.0% not appreciating that UV conditions peak at solar noon; and 23.3% of 22-44 year olds confusing the UVI with a "burn-time" measure. People who do not understand the UVI are unlikely to utilise it effectively. It therefore remains possible that utilisation of the UVI remains low because understanding is poor. Future efforts to improve utilisation of the UVI, particularly among those looking at new display formats, may therefore be ineffective, unless they also incorporate strategies to facilitate understanding of the measure.