How are Non-numerical Prognostic Statements Interpreted and are They Subject to Positive Bias?

Objectives: Frank, clear, communication with family members of terminally-ill or incapacitated patients has important implications for well being, satisfaction with care, and sound decision making. However, numerical prognostic statements, particularly more negative ones, have been found to be interpreted in a positively-biased manner. Less precise non-numerical statements, preferred by physicians, and particularly statements using threatening terms (“dying” vs. “surviving”) may be even more subject to such biases. Methods: Participants (N = 200) read non-numerical prognostic statements framed in terms of dying or surviving and indicated their interpretation of likelihood of survival. Results: Even the most extreme statements were not interpreted to indicate 100% likelihood of surviving or dying, (e.g., “they will definitely survive,” 92.77%). The poorness of prognoses was associated with more optimistically biased interpretations but this was not, however, affected by the wording of the prognoses in terms of dying versus surviving. Conclusions: The findings illuminate the ways in which commonly-used non-numeric language may be understood in numeric terms during prognostic discussions and provide further evidence of recipients’ propensity for positive bias