Pharmaceutical pictograms to improve textual comprehension: A systematic review

Written instructive information for the patient is key in pharmaceutical care. However, the preexisting literature agrees on the discordance between the readability of written medication messages intended for patients. The aim of our work was to systematically review the available evidence on the effect of pharmaceutical pictograms as elements that facilitate understanding of the text in primary or secondary medication packaging. A parallel systematic search was conducted of the literature covering evidence of the effect of including pictograms in primary or secondary packaging on comprehension by potential users or caregivers up to April 9, 2023. The databases consulted were Scopus, MEDLINE and Web of Science. Only randomized controlled studies, whose main outcome measure was comprehension, were included. Only 8 papers met our search criteria. In most of the included studies, the intervention of including pictograms improved participants' performance in comprehending instructions. A debatable methodological quality, and differences in the target population, textual complexity of the materials or the cultural affinity of the pictograms with the target population in each study, could have had a decisive influence on the results. The heterogeneity in the design of each study poses a significant barrier to establishing commonalities and generalizing the results. This heterogeneity also prevented us from conclusively confirming the usefulness of pictograms complementary to instructional text in improving the comprehension of instructions for the rational use of medicines.