Strategies to optimize comprehension of numerical medication instructions: A systematic review and concept map

To develop evidence-based recommendations for improving comprehension of quantitative medication instructions. This review included a literature search from inception to November 2021. Studies were included for the following: 1) original research; 2) compared multiple formats for presenting quantitative medication information on dose, frequency, and/or time; 3) included patients/lay-people; 4) assessed comprehension-related outcomes quantitatively. To classify the studies, we developed a concept map. We weighed 3 factors (risk of bias in individual studies, consistency of findings among studies, and homogeneity of the interventions tested) to generate 3 levels of recommendations. Twenty-one studies were included. Level 1 recommendations are: 1) use visualizations of medication doses for liquid medications, and 2) express instructions in time-periods rather than times per day. Level 2 recommendations include: validate icons, use panels or tables with explanatory text, use visualizations for non-English speaking populations and for those with low health literacy and limited English proficiency. Visualized liquid medication doses and time period-based administration instructions improve comprehension of numerical medication instructions. Use of visualizations for those with limited health literacy and English proficiency could result in improved outcomes. Practitioners should use visualizations for liquid medication instructions and time period-based instructions to improve outcomes. •A novel concept map can be used to classify quantitative medication instructions.•Using visualized liquid medication doses improves comprehension of instructions.•Time period-based instructions improves comprehension of medication instructions.•Medication instruction images may improve outcomes for limited health literacy.•Using validated images in medication instructions may improve outcomes.