Legibility of USP pictograms by clients of community pharmacies in Portugal

Background Effective and safe use of medicines depends on patients' good understanding of the pharmacotherapy. Pictograms are a communication tool, as complement of verbal/written information, to facilitate drug use and, avoiding errors, being useful for drug effectiveness and safety. Objective To assess the ability of pharmacy's clients, in understanding USP pictograms, establishing the relationship with their socio demographic profiles. Setting The study was developed in community pharmacies, in Lisbon region. Methods Cross sectional study, carried out in pharmacies in Lisbon. A structured questionnaire was used in pharmacies clients of 18 years old and above. Legibility of fifteen USP pictograms was studied using ISO and ANSI criteria. Correlation between the legibility of pictograms and pharmacies clients' demographic profile (age, gender, scholarship, frequency of medicines use) was evaluated. SPSS data base version 18 was used for descriptive analysis. Main outcome measure Legibility of fifteen United States Pharmacopeia (USP) pictograms and, its relationship with clients' demographic data (scholarship degree, age, frequency of medicines use and, gender) was studied. Results From 751 responders, ten pictograms were legible by ISO and seven by ANSI. More than 30 % of the responders weren't able to understand five of the pictograms. It was found statistically significant relationships between some the understanding of some pictograms and clients' scholarships degree, age and frequency of medicines use. Conclusion It was found that not all the fifteen tested USP pictograms were correctly comprehended by Portuguese pharmacies' clients, having found correlations with scholarship degree, daily use of medicines and age group, for some pictograms. To ensure the effectiveness of USP pictograms it is advisable to test patients' comprehension, before their use in general practice.