Background: Medication errors are a major health concern among the elderly causing a wide range of adverse events. Drug label misreading is one such problem that contributes to these errors. Therefore, evidence suggesting appropriate characters on drug labels is required as a useful instruction for improving understanding.

Objective: To investigate the appropriate characters on drug labels for the elderly, both in reading accuracy and satisfaction dimensions.

Materials and Methods: A quasi-experimental study was conducted on 56 elderly Thai patients with a mean age of 65.9±5.2 and including 26 males and 30 females. Six drug labels were provided for all participants to read, with three different fonts, which were Angsana New, Microsoft San Serif, and TH Far Kwang, and two character-sizes at 0.22 and 0.26 cm in height. Their reading voices were recorded to examine reading accuracy, with words corrected per minute (WCM). The satisfaction scores were obtained by an opinion assessment in three components, which were ease of reading, aesthetically pleasing, and overall satisfaction.

Results: The results showed that Angsana New, with a size of 0.26 cm, presented the highest score in WCM (mean±SD: 148±28.3 words per minute), and was shown to have the most satisfaction score. A generalized linear mixed model revealed that a larger character size and Angsana New, with a size of 0.26 cm, were significantly associated with higher WCM (p=0.003 and 0.005, respectively), whereas increasing age was significantly associated with lower WCM (p=0.035).

Conclusion: The size of 0.26 cm of Angsana New and Microsoft San Serif were appropriate for use in drug labeling for elderly Thai patients.

Keywords: Drug label; Elderly; Character size; Fonts

DOI: 10.35755/jmedassocthai.2022.11.13697

Received 30 March 2022 | Revised 9 September 2022 | Accepted 27 September 2022