Influence of Explanatory Images on Risk Perceptions and Treatment Preference

The aim of this study was to examine whether providing patients with a series of balance scales (BS), depicting a reciprocal relationship between achieving disease control and increasing the risk of infection, influences treatment preference.

Participants were randomized to receive a description of a medication in which risk of infection was relayed using 1 of 4 formats, including numbers only, numbers + icon array (IA), numbers + BS, or numbers + IA + BS (i.e., combination). We compared the likelihood of starting the medication across the 4 formats, and evaluated whether the influence of risk formats varied by numeracy and gist risk appraisals.

The mean ± SE likelihood of starting the medication was higher among participants randomized to the combination format (3.85 ± 0.09) compared to those who viewed the BS (3.56 ± 0.09; P = 0.0222) or numbers-only formats (3.51 ± 0.09; P = 0.0069). Viewing an IA alone was associated with a lower likelihood of starting the medication among participants lower in numeracy and endorsing a risk-avoidant noncompensatory gist risk appraisal. Conversely, viewing an IA (with or without the BS) was associated with a greater likelihood of starting the medication among patients with higher numeracy and compensatory risk appraisals.

Adding explanatory images to IAs increases patient likelihood to take a medication in those with low numeracy and a noncompensatory gist risk appraisal. Explanatory images may be a feasible approach to improve willingness to try medication among subjects who are especially risk averse and believe that any risk is unacceptable.