Abstract
BACKGROUND: To inform their health decisions, patients may seek narratives describing other patients' evaluations of their treatment experiences. Narratives can provide anti-treatment or pro-treatment evaluative meaning that low-numerate patients may especially struggle to derive from statistical information. Here, we examined whether anti-vaccine (v. pro-vaccine) narratives had relatively stronger effects on the perceived informativeness and judged vaccination probabilities reported among recipients with lower (v. higher) numeracy. METHODS: Participants ( n = 1,113) from a nationally representative US internet panel were randomly assigned to an anti-vaccine or pro-vaccine narrative, as presented by a patient discussing a personal experience, a physician discussing a patient's experience, or a physician discussing the experiences of 50 patients. Anti-vaccine narratives described flu experiences of patients who got the flu after getting vaccinated; pro-vaccine narratives described flu experiences of patients who got the flu after not getting vaccinated. Participants indicated their probability of getting vaccinated and rated the informativeness of the narratives. RESULTS: Participants with lower numeracy generally perceived narratives as more informative. By comparison, participants with higher numeracy rated especially anti-vaccine narratives as less informative. Anti-vaccine narratives reduced the judged vaccination probabilities as compared with pro-vaccine narratives, especially among participants with lower numeracy. Mediation analyses suggested that low-numerate individuals' vaccination probabilities were reduced by anti-vaccine narratives-and, to a lesser extent, boosted by pro-vaccine narratives-because they perceived narratives to be more informative. These findings were similar for narratives provided by patients and physicians. CONCLUSIONS: Patients with lower numeracy may rely more on narrative information when making their decisions. These findings have implications for the development of health communications and decision aids.