What do men understand about lifetime risk following genetic testing? The effect of context and numeracy

Objective: Genetic testing for gene mutations associated with specific cancers provides an opportunityfor early detection, surveillance, and intervention (Smith, Cokkinides, & Brawley, 2008). Lifetime riskestimates provided by genetic testing refer to the risk of developing a specific disease within one’slifetime, and evidence suggests that this is important for the medical choices people make, as well as theirfuture family and financial plans. The present studies tested whether adult men understand the lifetimerisks of prostate cancer informed by genetic testing. Method: In 2 experiments, adult men were asked tointerpret the lifetime risk information provided in statements about risks of prostate cancer. Statementformat was manipulated such that the most appropriate interpretation of risk statements referred to anabsolute risk of cancer in Experiment 1 and a relative risk in Experiment 2. Results: Experiment 1revealed that few men correctly interpreted the lifetime risks of cancer when these refer to an absoluterisk of cancer, and numeracy levels positively predicted correct responding. The proportion of correctresponses was greatly improved in Experiment 2 when the most appropriate interpretation of riskstatements referred instead to a relative rather than an absolute risk, and numeracy levels were lessinvolved. Conclusion: Understanding of lifetime risk information is often poor because individualsincorrectly believe that these refer to relative rather than absolute risks of cancer