Objective: Instructions contained in over-the-counter medicine package inserts can be hard to read because of the limited printing space.  Pictograms are one means of helping users to understand important information.  However, few pictogram systems have been reliably and validly evaluated.  Therefore, a new method was developed to improve the clarity of each illustration and the legitimacy as a pictogram for conveying information important.
Methods: Four creators developed 69 illustrations, each of which expressed one of 24 instructions in the package insert of an H2 blocker.  In a survey, participants (449 university undergraduate and graduate students and 103 pharmacy users) were asked to describe the possible meaning of each illustration and to provide their personal suggestions for improvement.  To evaluate comprehension of information, each instruction was broken into two or three different parts.  Comprehension level was calculated by: (number of people who answered correctly) × 100 / (total number of respondents).  Existing pictograms were included to compare comprehension levels for the same instructions.
Results: Using 67% as the minimum standard for comprehension, we classified each illustration into one of three categories: “no need for improvement,” “need for partial improvement,” and “need for total improvement.”  The students and pharmacy users tended to accurately interpret the possible meanings of illustrations that were familiar to them.
Conclusion: Breaking one instruction of the package insert into a few important pieces of information was useful for determining the level of improvement needed for each illustration.  Evaluating how well each illustration conveys important information in the instructions through two steps was also beneficial, which are to improve the illustration’s clarity with students and its legitimacy among pharmacy users for fulfilling the intended functions of a pictogram.