Influence of Font Sizes on the Readability and Comprehensibility of Package Inserts Dr. Jörg Fuchs1,2, Tina Heyer1,3, Diana Langenhan1,3, and PD Dr. Marion Hippius3 PAINT-Consult1, Jena (Germany), Department of Drug Regulatory Affairs,
Institute of Pharmacy, University of Bonn2, Bonn (Germany), and
Institute of Clinical Pharmacology, Friedrich Schiller University3, Jena (Germany) The new European readability guideline draft for package inserts recommends a minimal font size of 12 pt and 16 to 20 pt for medicines which are more frequently used by visually impaired patients. However, research results illustrate that smaller font sizes are easier to read.
Therefore, the written readability test was used to investigate how font size influenced the information locatability and comprehensibility. Fifteen questions focusing on the package insert contents and 17 questions focusing on participants’ opinions were compiled. The study examined one package insert available on the German medicines market and its optimized model version. Both were printed in 9 different font sizes, between 7 and 16 pt.
The 205 participants were significantly more often unable to locate and understand information in the original, 6.7 to 16.0 % and 15.0 to 27.0 %, as compared to the model, 2.8 to 6.7 % and 9.2 to 14.7 %. Font size only had a minor influence on locatability compared to other optimization possibilities, optimal being between 9 to 12 pt. However, larger font sizes decreased the locatability, while comprehensibility was not influenced.
On the basis of these findings the new readability guideline draft for package inserts should be reconsidered. The 9 pt font size is ideal and more realistic and therefore should be recommended in this guideline, as the minimum used in package inserts. |
