Gerd Gigerenzer, of the Max Planck Institute for Human Development in Berlin, and colleagues conducted a survey of over 10,200 people from nine European countries to assess perceptions of cancer-specific mortality reduction associated with mammography and prostate-specific antigen screening, and to determine the sources of information they rely on.
The authors found that the majority of participants have a dramatic overestimation of the benefits of such tests, and that doctors and other sources of information appear to have little impact on improving knowledge of the level of benefit. Ninety-two percent of women overestimated the benefit of mammography screening by at least one order of magnitude or reported they did not know; 89% of men overestimated the benefit of prostate-specific antigen screening or did not know.
"Knowing the benefit of a treatment is a necessary condition for informed consent and rational decision making," the authors write.
In an accompanying editorial, Lisa M. Schwartz, M.D., and Steven Woloshin, M.D. of the Dartmouth Institute for Health Policy & Clinical Practice in Hanover, N.H., point out that accurate screening messages should be more prominent and include risks associated with overdiagnosis and overtreatment.
The editorialists call some of the researchers' methods biased toward overestimation and question if participants are truly representative of the European Union, but do acknowledge the study's contribution. "These cautions...do not diminish the importance of the study...," they write. "We need to move from selling screening to helping people realize that screening is a genuine choice..."