CONTRASTING PREFERENCES BETWEEN SURROGATE DECISION-MAKERS AND PHYSICIANS ON USING NUMERIC ESTIMATES TO PREDICT LONG-TERM OUTCOMES IN CRITICALLY-ILL TRAUMATIC BRAIN INJURY PATIENTS – RESULTS FROM A QUALITATIVE STUDY

Purpose: Making good decisions about the continuation of medical care in hospitalized critically-ill traumatic brain injury (ciTBI) patients requires surrogate decision-makers (“surrogates”) to understand the possible long-term outcomes, with or without continuing medical care. Most surrogates expect physicians to predict what these long-term outcomes may be. To date, no research has examined and compared surrogates’ and physicians’ preferences with respect to communication of this prognostic information. The objective of this study was to examine the communication preferences of surrogates of ciTBI patients and physicians during the prediction of possible long-term outcomes of ciTBI patients.

Methods: We conducted semi-structured interviews with 16 purposefully sampled surrogates of previously hospitalized ciTBI patients (up to two years from injury) recruited from two level-1 trauma-centers in the Northeast and Mid-Atlantic region, and 20 subspecialty physicians (neurocritical care,neurosurgery,trauma,palliative care) from seven academic hospitals in the Northeast,Mid-Atlantic,South,West, and Midwest. We explored the factors that physicians consider when they make predictions about long-term outcomes, and preferences for communicating these predictions for both physicians and surrogates. Two independent reviewers analyzed transcribed interviews using deductive and inductive approaches (NVIVO-software), with adjudication by a third reviewer when necessary. The sample size was determined by theme saturation.

Results: Overall, 82% of surrogates stated a preference for numeric estimates from the physicians to predict outcomes, as compared to purely qualitative predictions(“highly likely”or “unlikely”). All surrogates explained that numerical values were “more direct”,“clearer, more concise,and less confusing” than descriptive predictions. In contrast, 75% of physicians stated that they do not typically give numeric predictions when discussing outcomes in ciTBI due to distrust in the accuracy of existing models: “Better have good data to do that with, and most often, we do not.”While physicians were all aware of the surrogates’ preferences for numeric risk prediction, they also voiced concern that surrogates might misinterpret numeric risk estimates: “Families will often hook onto those numbers and make an absolute judgment…they become simplified and [these numbers are] used against you later.”

Conclusion: We found lack of concordance between physicians and surrogate decision-makers of ciTBI patients regarding the communication of predicted long-term outcomes. Shared-decision making tools in ciTBI could potentially help set more realistic expectations by explaining to surrogates the limitations of risk prediction models and helping them to better interpret probabilistic information.