Comparing comprehensibility of standard and enhanced prescription medicine labels: a randomized simulation

The objective of this study is to develop and user-test the comparative effectiveness of two enhanced label designs to improve comprehension of patients with low English proficiency versus a standard label representative of the pharmacist-affixed medicine labels currently used in practice. Using a randomized two-group study design, 66 participants from Sydney, Australia were allocated to view a set of standard labels followed by a set of enhanced labels named 'linguistically enhanced labels' or 'linguistically and graphically enhanced labels'. Each set of labels depicted medicine directions of three levels of complexity, which participants viewed consecutively. The 'enhanced labels' incorporated several features documented in the literature as improving understanding of low-health-literate/linguistically compromised individuals such as translated directions in a language the person is more proficient in, numeric presentations of numbers/counts, carriage returns and graphic depiction of directions. A user-testing questionnaire relating to comprehensibility was conducted after each label was viewed. Differences in comprehensibility were assessed using a generalized linear model, Cochran-Mantel-Haenszel test for trend and a chi-square test. Results indicated significant improvements in comprehensibility with both types of enhanced labels compared with standard labels (P < 0.0001). The 'linguistically and graphically enhanced label' improved comprehensibility of the most complex directions to a greater extent than the 'linguistically enhanced label' (P < 0.0001). This study has highlighted the scope for improvement of existing pharmacist-affixed prescription medicine labels to ensure better understanding by individuals with low English proficiency. The enhanced labels trialled presented a means with which this may be achieved through the incorporation of key design elements, such as simpler, translated and graphically supported directions.