Effects of Anti- Versus Pro-Vaccine Narratives on Responses by Recipients Varying in Numeracy: A Cross-sectional Survey-Based Experiment

Abstract

Purpose 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 especially low-numerate patients struggle to derive from statistical information. Here, we examined whether anti-vaccine (vs. pro-vaccine) narratives had relatively stronger effects on the perceived informativeness and judged vaccination probabilities reported among recipients with lower (vs. higher) numeracy. Methods Participants (n=1113) 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 experience 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 how informative they perceived the narratives to be. 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 judged vaccination probabilities compared to 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 – due to their perceiving narratives as more informative. These findings held whether narratives were provided by patients or physicians. Conclusions Patients with lower numeracy may rely more on narrative information when making their decisions. Findings have implications for the development of health communications and decision aids.

Age differences in financial decision making:The benefits of more experience and less negative emotions

“…Older age was unrelated to motivation to think hard about complex problems and numeracy. As discussed in more detail below, the latter is in line with other studies of relatively educated samples (Bruine de Bruin et al, ; Låg et al, ; McNair et al, in press; Sinayev et al, ; Weller et al, ).…”

“…As a result, the range of numeracy scores may have been restricted, thus limiting our ability to uncover correlations of numeracy with, say, age (see also Sinayev et al, ). Other studies with relatively educated samples have also found no significant correlation between numeracy and age (Bruine de Bruin et al, ; Låg et al, ; McNair et al, in press; Sinayev et al, ; Weller et al, ). Yet the tradition to recruit younger adults from among college students and older adults from the community may have confounded older age with lower educational attainment and therefore exaggerated the correlation between older age and lower numeracy skills (Strough, Parker, & Bruine de Bruin, ).…”

“…These findings potentially reflect the cognitive demands of numerical computations (Del Missier, Mäntylä, & Bruine de Bruin, 2012), which may be more difficult for older adults due to age-related decline in fluid cognitive ability Park & Reuter-Lorenz, 2009). However, numeracy does not consistently correlate with age across studies (e.g., Bruine de Bruin, Wallin, Parker, Strough, & Hanmer, 2017;Låg, Bauger, Lindberg, & Friborg, 2014;McNair, Okan, Hadjichristidis, & Bruine de Bruin, in press;Sinayev, Peters, Tusler, & Fraenkel, 2015;Weller et al, 2013). In relatively well-educated internet samples, the range of numeracy scores may be restricted, thus limiting the potential for uncovering correlations between numeracy and age (see Sinayev et al, 2015).…”

Despite high objective numeracy, lower numeric confidence relates to worse financial and medical outcomes

“…Decisions of the less objectively numerate instead are more vulnerable to decision heuristics, mental shortcuts used in judgments and choices (21)(22)(23). For example, they succumb to framing effects and the compelling power of narratives, emotions, and concrete, easy-to-evaluate information (24)(25)(26). As a result, the less objectively numerate tend to make worse decisions when numbers are involved, even after controlling for nonnumeric intelligence.…”

No evidence that omission and confirmation biases affect the perception and recall of vaccine-related information

“…that make them especially "sticky" in human minds [60]. Importantly, the same characteristics of these messages might also be used to promote vaccination [20,61], providing a more optimistic prospect for countering anti-vaccination information.…”