RESPONSES TO NARRATIVES BY RECIPIENTS VARYING IN NUMERACY

Purpose: Evidence-based medicine and shared decision making are central tenets of modern health care. Sharing information with patients is presumed to improve patients’ understanding of their options and to increase health care providers’ understanding of patient preferences.  Health care providers may share different types of evidence with their patients, including statistical evidence based on scientific studies and narrative evidence based on their experiences.  Studies have shown that especially low-numerate patients are swayed by anti-vaccine narratives from other patients.  However, patients’ responses to pro-vaccine or physician-provided narratives have rarely been evaluated.  Here, we examined how recipients’ numeracy was related to their responses to pro-vaccine and anti-vaccine narratives from different sources, as well as to the process through which the presented narratives influenced their vaccination intentions.

Method(s): We recruited 1113 participants from a US national internet panel. They received different types of narratives about flu shots, in addition to a standard pamphlet from the Centers for Disease Control and Prevention (CDC).  Participants were randomly assigned to a narrative that was (a) pro-vaccine or anti-vaccine, (b) presented by either a patient discussing their own experience, a physician discussing another patient’s experience, or a physician discussing the experience of 50 patients, and (c) presented before or after the CDC pamphlet.  Pro-vaccine narratives described the flu experiences of patients who got the flu after not getting a flu shot, and anti-vaccine narratives described the flu experiences of patients who got the flu after getting a flu shot.  Narratives were equivalent in length and wording.  Participants subsequently indicated the probability that they would get vaccinated, perceptions of flu risk and severity with and without the flu shot, and their ratings of the quality of the presented narratives.

Result(s): Low-numerate individuals reported lower vaccination intentions, especially after reading anti-vaccine (vs. pro-vaccine) narratives.  A multi-mediation analysis suggested that low-numerate individuals’ vaccination intentions were reduced by anti-vaccine narratives and boosted by pro-vaccine narratives, due to their perceiving narratives as relatively better than did high-numerate individuals.  These findings held across other conditions, including whether narratives were provided by patients or physicians.

Conclusion(s): Health-care providers may add narrative information when presenting statistical evidence to inform patients’ decisions.  As compared to high-numerate recipients, low-numerate recipients seem to rely more on such narrative information when making their decisions.