Effect of Tabular and Icon Fact Box Formats on Comprehension of Benefits and Harms of Prostate Cancer Screening: A Randomized Trial

Background. Fact boxes employ evidence-based guidelines on risk communication to present benefits and harms of health interventions in a balanced and transparent format. However, little is known about their short- and long-term efficacy and whether designing fact boxes to present multiple outcomes with icon arrays would increase their efficacy. Method. In study 1, 120 men (30–75 y) completed a lab study. Participants were randomly assigned to 1 of 3 fact box formats on prostate cancer screening: a tabular fact box with numbers, a fact box with numbers and icon array, and a fact box with numbers, separate icon arrays, and text to describe each benefit and harm. Comprehension of information (while materials were present) and short-term knowledge recall were assessed. Study 2 recruited an online sample of 244 German men (40–75 y). Participants were randomly assigned to 1 of the 3 fact box formats or widely distributed health information, and knowledge was assessed at baseline, shortly after presentation, and at 6-mo follow-up, along with comprehension while materials were present. Results. In both studies, comprehension and knowledge-recall scores were similar when comparing tabular and icon fact boxes. In the 6-mo follow-up, this positive effect on knowledge recall disappeared. Fact boxes increased knowledge relative to baseline but did not affect decision intentions or perceptions of having complete information to make decisions. Conclusions. This study shows that fact boxes with and without icon arrays are equally effective at improving comprehension and knowledge recall over the short-term and are simple formats that can improve on current health information. Specifically, if fact boxes are used at the time or immediately before a decision is made, they promote informed decisions about prostate cancer screening.