Exploring the human factors of medication errors in community pharmacy: a mixed methods study
Authors: Balchaites A , McCarthy S , Fleming A 
Published: April 2022

Abstract

Introduction
Medication errors and near misses in the community pharmacy dispensing process have the potential to adversely impact patient safety. The World Health Organisation has identified the importance of Human factors (HF) in the Patient Safety Curriculum guide (1). However, there is a lack of knowledge on how HF principles have or could be applied in the community pharmacy setting. Adopting a HF approach and using qualitative methods can provide in-depth understanding of factors that contribute to these errors, and contribute to intervention development that may improve patient safety.

Aim
The study aims to investigate the factors contributing to medication dispensing errors and near misses in community pharmacy, and to gather pharmacists’ views of these factors and how these could be mitigated.

Methods
Three Irish community pharmacies were recruited and provided details of the last ten dispensing errors or near misses which occurred. Each error was mapped to the Hierarchical Task Analysis (HTA) steps developed for this study, and mapped to the Systematic Human Error Reduction and Prediction Approach (SHERPA) framework (2). A detailed report was prepared for each pharmacy outlining the error analysis, with recommendations to prevent the errors in future. A qualitative semi-structured interview was conducted with the three pharmacists in the recruited pharmacies to discuss the report, and analysed by thematic analysis.

Results
A total of 30 medication errors/near misses were analysed (10 errors reached the patients and were not administered). The HTA developed outlines 185 subtasks potentially involved in dispensing a prescribed medication. On mapping to the SHERPA framework, selection-based errors were the most frequently reported error category (21/30, 70%); this included incorrect product selection from the shelf (17/30, 56.7%) and incorrect product selection at the point of computer entry (4/30, 13.3%). Of the 75 HTA steps involved across the 30 errors, the most frequent point of error was in the gathering medication steps (47/75, 62.7%), followed by the pharmacist accuracy check steps (16/75, 21.3%) and patient mix up errors (5/30, 16.7%). The pharmacist interview themes found that cognitive burden, fatigue, distraction and staffing deficiencies were reported as increasing the risk of error and near miss. Knowledge gaps and inexperience with certain medications were also reported as contributing to errors. Recommendations to prevent errors included changes to the physical environment (e.g. using product shelf alerts), improved checking processes and taking short mental breaks.

Conclusion
This study found that the most common errors/near misses were at the product selection stage of dispensing, with pharmacy accuracy checks sometimes, but not always, detecting these before they reached the patient. Medication errors occur due to several varying and often interacting factors; cognitive burden and lack of standardised medication checking processes. Despite the small sample size and potential for social desirability bias in the interviews, this study has demonstrated how HF techniques can be applied to the dispensing process as a means of understanding and preventing error occurrence in the community pharmacy.

References
(1) Vosper H, Hignett S. A UK perspective on human factors and patient safety education in pharmacy Curricula. Am J Pharm Educ. 2017;82:6184.
(2) Sutherland A, Ashcroft DM, Phipps DL. Exploring the human factors of prescribing errors in paediatric intensive care units. Arch Dis Child 2019;104:588-595.