This investigation points to several potential mechanisms beyond simple misunderstandings that may underlie the prevalent discordance between physicians and surrogates about prognosis in patients with advanced illness. The quantitative portion of the study revealed a systematic optimism bias in how surrogates interpret statements indicating a poor prognosis. The qualitative portion revealed several explanations for this finding, including surrogates’ need to register optimism when patients are at high risk for death and surrogates’ belief that positive patient attributes lead them to outperform physicians’ grim prognostications.
Perhaps the most intriguing finding of our study is the systematic bias in how surrogates interpreted grim prognostic statements. The fact that surrogates were able to accurately interpret numerical statements expressing a high probability of a good outcome, but not those expressing a high risk for death, suggests that simple misunderstandings of numerical risk information are unlikely to explain the discordance. The qualitative portion of the study pointed to psychological biases rather than misunderstandings as the cause. In aggregate, these findings challenge the prevailing assumption in the medical literature that discordance between physicians and surrogates about prognosis is due largely to unclear disclosure by physicians or simple misunderstandings by surrogates (5
). These findings imply that helping surrogates attain realistic expectations about patients’ likely outcomes will be more complex than simply giving clear information.
We identified cognitive and psychological factors affecting how surrogates process
risk information that may contribute to their overly optimistic expectations. Some surrogates seem to doubt physicians’ ability to accurately predict death. This is not necessarily irrational in light of the complexity in predicting ICU outcomes and the empirical evidence documenting physicians’ inaccuracy in prognostication (25
). This finding alone does not fully explain surrogates’ optimistic interpretations, because skepticism about accuracy should result in a random distribution of interpretations rather than systematic optimism. Second, some surrogates reported that the positive attributes of the patient would help them outperform physicians’ expectations. This may express a valid insight about patient characteristics unknown to physicians. Alternatively, it may represent a cognitive bias known as illusory superiority, unrealistic optimism, or the “Lake Wobegon effect,” a cognitive bias that leads people to overestimate, in relation to others, their likelihood of experiencing positive outcomes and avoiding negative outcomes (26
Another theme emerging during the semistructured interviews that explained surrogates’ overly optimistic interpretations of grim prognostic information was their need to express optimism. This need may represent a coping strategy to help surrogates confront the emotional difficulty of having a critically ill loved one. Alternatively, it may represent an element of “magical thinking” that there is a causal link between the prognostic estimate they record and the patient’s outcome (27
). Sulmasy and colleagues (14
) recently documented a similar phenomenon among participants enrolled in phase 1 and 2 clinical trials. They found that participants recorded expectations of benefit that far exceeded what could reasonably be expected in early-phase clinical trials, which seemed to be due to participants’ belief that optimism is performative or the notion that positive thoughts and expectations may actually improve the chances of benefit (14
We found that some surrogates were not aware that they were interpreting physicians’ prognostications in optimistic ways. This suggests that the discordance about prognosis between physician and surrogates may be difficult to successfully remedy in clinical encounters without a great deal of awareness and skill by clinicians. This is especially important because not all optimism is ethically benign. In the context of surrogate decision making, unrealistic optimism may lead to decisions that do not reflect the true values of the patient. For example, if self-protection makes a surrogate emotionally unable to acknowledge when a patient has a very poor prognosis, the surrogate may request ongoing use of life support when the patient’s values suggest that a transition to comfort measures only is more appropriate.
Previous studies have reported that laypersons interpret qualitative probability statements in highly variable ways (8
), causing many to advocate for the use of quantitative language when communicating risk in the medical setting (10
). Our findings of wide variability in how numerical statements are interpreted suggest that the magnitude of benefit in using numbers may not be as great as previously thought. Furthermore, the qualitative results reveal that for some surrogates it is the “gist” of the prognostic information (that is, the take-home message), rather than the exact numerical value, that is useful for decision making. In light of the emerging importance of gist to decision making (29
), as well as the frequent lack of precision in clinicians’ prognostic estimates for patients with advanced illness, there may be merit to exploring risk-communication strategies that focus on conveying the gist of the information rather than on assuring verbatim understanding of very precise prognostications.
Our study has several limitations. First, we asked surrogates to interpret hypothetical prognostic statements in a questionnaire format. This may not fully replicate the circumstances and emotional responses that arise in actual clinician–family encounters. However, all participants were actively engaged in surrogate decision making for a critically ill patient, which increases the likelihood that participants’ responses capture those experienced by surrogates in ICUs. Second, we interviewed only a subset of 15 participants about their inaccurate interpretations of quantitative prognostic statements. It is possible that interviewing a larger subset would have yielded more reasons to explain our trend or further clarified our findings. However, we reached a point of thematic saturation (16
), suggesting that this is unlikely. Third, there are inherent limitations in individuals’ reported explanations for complex behaviors (31
). Therefore, mechanisms other than those reported by participants could also have contributed. Fourth, we enrolled participants only within the ICU or waiting room. Surrogates who are frequently present in the hospital might differ from those who are infrequently in the hospital. Fifth, there is no gold standard for measuring individuals’ risk perceptions; we chose the probability scale because it is widely used and allows for simple statistical analysis. Finally, we studied surrogate decision makers rather than patients; it is unknown whether patients experience a different cognitive and psychological process that affects risk perception.
In conclusion, our data point to causes beyond simple misunderstandings that explain the discordance between physicians and surrogates about prognosis in patients with advanced illness. Accordingly, interventions to improve this element of decision making will probably require attention not only to the clarity with which risk information is conveyed but also to the emotional and psychological factors that affect how individuals process such information. Clinicians who communicate with surrogate decision makers in the care of incapacitated patients should be aware of the diverse causes for discordance about prognosis; researchers should develop and test communication strategies designed to attend to the emotional and cognitive biases that arise in surrogate decision making.