Verbal Descriptions of the Probability of Treatment Complications Lead to High Variability in Risk Perceptions: A Survey Study.

Objective: To assess whether different methods for communicating the probability of treatment complications for operative and nonoperative appendicitis treatments result in differences in risk perception.

Background: Surgeons must communicate the probability of treatment complications to patients, and how risks are communicated may impact the accuracy and variability in patient risk perceptions and ultimately their decision making.

Methods: A series of online surveys of American adults communicated the probability of complications associated with surgical or antibiotic treatment of acute appendicitis. Probability was communicated with verbal descriptors (eg, "uncommon"), point estimates (eg, "3% risk"), or risk ranges (eg, "1% to 5%"). Respondents then estimated the probability of a complication for a "typical patient with appendicitis." The Fligner-Killeen test of homogeneity of variance was used to compare the variability in respondent risk estimates based on the method of probability communication.

Results: Among 296 respondents, variance in probability estimates was significantly higher when verbal descriptions were used compared to point estimates ( P < 0.001) or risk ranges ( P < 0.001). Identical verbal descriptors produced meaningfully different risk estimates depending on the complication being described. For example, "common" was perceived as a 45.6% for surgical site infection but 61.7% for antibiotic-associated diarrhea.

Conclusion: Verbal probability descriptors are associated with widely varying and inaccurate perceptions about treatment risks. Surgeons should consider alternative ways to communicate probability during informed consent and shared decision-making discussions.