Table 1. Summary of guiding principles for developing risk assessment communications derived from the literature review.

Guiding Principles for Risk Assessment Communications

Profile development process Involve different target groups and adapt prototype designs to focus on lay understanding. Presentation and communication of risk assessment criteria Adapt the layout, structure, and design of texts to ensure readability for less educated groups (e.g., using a question-answer format, clear structure of texts, use of examples, color design; [15]). Where possible, quantify or categorize risks and use numbers to communicate the magnitude of risks. A recommendation against using verbal labels unless accompanied by numbers was advised, as verbal labels are interpreted inconsistently [15, 28, 29, 32]. Define a clear reference class when reporting numbers (e.g., frequencies or percentages; [15, 27, 29, 32]). Provide probability and severity information separately for each concrete health impairment. Consistent with recommendations on communicating scientific uncertainty, include the quality of evidence despite few studies on how best to represent this information. As a first step, communicate non-quantifiable uncertainty as a predefined categorization of uncertainty (e.g., low, medium, high), otherwise as a qualifying verbal statement based on an evaluation of aspects including study limitations, consistency of results, indirectness of evidence, imprecision, and reporting bias [33, 34]. Add a description of specific actions that would reduce the risk for consumers. Criteria lacking evidence base Dose-response thresholds: no studies on how to best communicate these could be identified. Ideas were generated within the research team (e.g., depicting a thermometer, a curve, colour gradients, etc.). Use of analogies for communicating about complex concepts