This study examined the perceived AD risk of individuals who accurately recalled their communicated AD risk. Among those who accurately recalled their communicated risk, nearly one half did not fully adjust their perceived personal risk of AD to match their communicated AD risk estimate. Our findings suggest that baseline perceived AD risk, baseline feelings of control over AD, and genotype information are the strongest predictors of these discordant risk perceptions.
We found that participants modify their perceived personal risk of AD in the direction of the mean communicated risk after genetic education and counseling. However, as a group, the posttest mean perceived personal risk remains somewhere in between baseline the mean perceived personal risk and the mean communicated risk. This pattern held true within each of the observed sociodemographic subgroups ().
In addition, we observed wide variation in posttest perceived personal risk among individual study participants who accurately recalled their AD risk estimate. Nearly one third of the participants with accurate risk recall reported their posttest perceived personal risk to be higher than their recalled risk, which we referred to as being discordant high. Conversely, approximately 15% felt that their AD risk was lower than their accurately recalled risk and were subsequently referred to as being discordant low. Our logistic regression analysis found that greater baseline levels of perceived personal risk were predictive of being in the discordant-high category, whereas greater baseline feelings of control over developing AD and testing positive for one more APOE ε4 alleles were each predictive of being in the discordant-low group.
There are several plausible explanations as to why some participants do not adjust their perceived disease risk to match their personalized health risk assessments. One explanation involves an anchoring-and-adjustment bias,45
which is described as the adjustment of perceived risk toward—but not equal to—the objective risk provided by health care providers. Our results shown in illustrate this phenomenon. In addition, the significant relationship between higher baseline levels of perceived risk and being in the discordant-high group may be related at least in part to anchoring-and-adjustment biases.
Similar results from two recent studies suggest that the anchoring-and-adjustment bias exists across various diseases and risk groups. Weinstein et al.29
surveyed 353 individuals scheduled for nonurgent primary care appointments immediately before and after a computer-based presentation on colon cancer risks. Among the participants randomized to receive a personalized colorectal cancer risk estimate, only 45% reported agreement between their recalled communicated risk and personal risk perception, whereas 47% perceived their risk to be higher than the communicated risk estimate.29
Discordance between participants' postintervention perceived risk and their self-reported communicated risk was associated with their baseline perceived risk of colon cancer. Gurmankin et al.28
examined the risk recall and perception of 108 women who received genetic counseling for (1) their risk of carrying a mutation in the BRCA1/2
genes that confer high risk of breast and/or ovarian cancer and (2) their risk of being diagnosed with breast cancer. Although the group's postcounseling perceived risks were significantly higher than their recalled communicated risks, they were also significantly lower than their baseline perceived risk.28
In addition to the potential subconscious anchoring-and-adjustment bias, participants may have made rational adjustments to their risk estimates based on their understanding of less well-defined risk or protective factors that are not included in the REVEAL study's AD risk calculations. For example, participants who regularly engage in rigorous mental or physical activity may have perceived their personal AD risk to be somewhat lower than the communicated risk, given their beliefs about the protective effects of their lifestyle. Although there has been a considerable amount of lay press coverage of the potential AD risk-reducing benefits of mental and physical exercise, the risk estimates used in this study do not incorporate this information.30
Future studies in this area should ascertain what, if any, additional objective factors participants consider when interpreting their disease risk.
Although participants may be incorporating unmeasured risk factors into their perceived personal risk of AD, it is also likely that individual attributes, such as coping style, influence risk perception.19
Previous work with participants in the first REVEAL study clinical trial suggests that receiving a personalized AD risk estimate may increase feelings of control or reduce feelings of uncertainty, thereby serving both problem-focused and emotion-focused coping mechanisms.46
Our current finding that APOE ε
4 positive individuals are more likely to be in the discordant-low group also suggests that minimizing one's perceived AD risk is another a way to cope with unfavorable risk information. This explanation is supported by the work of Etchegary and Perrier,42
who provide a comprehensive review of “defensive processing of threatening health information.” In brief, individuals may use various cognitive mechanisms to cope with the distress related to the communicated risk estimate. Enhanced coping may be psychologically beneficial, but the associated risk minimization could be detrimental if it undermines positive health behaviors that the individual might have otherwise enacted.
This study has several limitations. As in most clinical trials, the sample was predominantly composed of individuals with high levels of education. In addition, educational materials and clinician reminders that emphasized the limitations of risk estimates may have given credence to participants' notions that their actual risk differed from their communicated risk. Future studies should consider assessing participants' perceptions of the precision and accuracy of the communicated risk and exploring reasons for discordance. It is also noteworthy that although the disclosure of AD risk estimates and their limitations was standardized across providers and study sites, participants were free to ask their clinician clarifying questions and engage in further conversation. We are unable to systematically evaluate or adjust for the content of such additional conversations, which could have had an effect on how the participant recalled or perceived their AD risk estimate. Finally, although the relatively high number of African American participants is strength of the study, the small number of African Americans in the discordant-high group limited this particular analysis.