The ubiquity and utility of the therapeutic misconception

The term “therapeutic misconception” was coined in 1982 by Paul Appelbaum, Loren Roth, and Charles Lidz. Appelbaum and his colleagues interviewed participants in several psychiatric studies, including a drug trial with a placebo control arm. Appelbaum's group found that many people were unaware of the differences between participating in a study and receiving treatment in the clinical setting. Rather than understanding these differences, study participants tended to believe that therapy and research were governed by the same primary goal: to advance the individual patient's best interests. Appelbaum's group labeled this mistaken belief the therapeutic misconception.

Advance directives as acts of communication: a randomized controlled trial

BACKGROUND

Instructional advance directives are widely advocated as a means of preserving patient self-determination at the end of life based on the assumption that they improve surrogates' understanding of patients' life-sustaining treatment wishes. However, no research has examined whether instructional directives are effective in improving the accuracy of surrogate decisions.

PARTICIPANTS AND METHODS

A total of 401 outpatients aged 65 years or older and their self-designated surrogate decision makers (62% spouses, 29% children) were randomized to 1 of 5 experimental conditions. In the control condition, surrogates predicted patients' preferences for 4 life-sustaining medical treatments in 9 illness scenarios without the benefit of a patient-completed advance directive. Accuracy in this condition was compared with that in 4 intervention conditions in which surrogates made predictions after reviewing either a scenario-based or a value-based directive completed by the patient and either discussing or not discussing the contents of the directive with the patient. Perceived benefits of advance directive completion were also measured.

RESULTS

None of the interventions produced significant improvements in the accuracy of surrogate substituted judgment in any illness scenario or for any medical treatment. Discussion interventions improved perceived surrogate understanding and comfort for patient-surrogate pairs in which the patient had not completed an advance directive prior to study participation.

CONCLUSIONS

Our results challenge current policy and law advocating instructional advance directives as a means of honoring specific patient wishes at the end of life. Future research should explore other methods of improving surrogate decision making and consider the value of other outcomes in evaluating the effectiveness of advance care planning.