Perceptions of absolute versus relative differences between personal and comparison health risk.
OBJECTIVE
To explain inconsistent results in previous attempts to determine whether, when presented with health risk information, people focus primarily on information about their own risk status or on a comparison with others.


METHODS
A randomized between-groups experiment in which participants were presented with hypothetical cardiac risk information. We examined whether affective responses were primarily sensitive to the relative difference between personal and comparison risk, rather than the absolute difference.


METHODS
Participants' negative affective response to the risk information.


RESULTS
When relative differences were held constant, participants' responses were independently influenced by both personal risk and comparative standing, effects that were greatly attenuated when absolute differences were held constant. When maintaining constant absolute differences, personal and comparison risk information appeared to interact.


CONCLUSIONS
Previous studies tended to maintain constant absolute risk differences and so may have underestimated the impact of personal risk information. Participants' responses were sensitive to the way the risk difference was constructed. Basing experimental design decisions on assumptions about the information participants will respond to can lead to misinterpretations of the basis of risk judgments.
Mason
Dan
D
General Practice and Primary Care Research Unit, Institute of Public Health, University of Cambridge, United Kingdom. dm316@medschl.cam.ac.uk
Prevost
A Toby
AT
Sutton
Stephen
S
D000328:Adult; D002318:Cardiovascular Diseases / Q000523:psychology*; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006306:Health Surveys; D006801:Humans; D020407:Internet; D008297:Male; D018570:Risk Assessment; D014342:Truth Disclosure; D006113:United Kingdom