Causes of prescribing errors in hospital inpatients: a prospective study

Summary

Background

To prevent errors made during the prescription of drugs, we need to know why they arise. Theories of human error used to understand the causes of mistakes made in high-risk industries are being used in health-care. They have not, however, been applied to prescribing errors, which are a great cause of patient harm. Our aim was to use this approach to investigate the causes of such errors.

Methods

Pharmacists at a UK teaching hospital prospectively identified 88 potentially serious prescribing errors. We interviewed the prescribers who made 44 of these, and analysed our findings with human error theory.

Findings

Our results suggest that most mistakes were made because of slips in attention, or because prescribers did not apply relevant rules. Doctors identified many risk factors—work environment, workload, whether or not they were prescribing for their own patient, communication within their team, physical and mental well-being, and lack of knowledge. Organisational factors were also identified, and included inadequate training, low perceived importance of prescribing, a hierarchical medical team, and an absence of self-awareness of errors.

Interpretation

To reduce prescribing errors, hospitals should train junior doctors in the principles of drug dosing before they start prescribing, and enforce good practice in documentation. They should also create a culture in which prescription writing is seen as important, and formally review interventions made by pharmacists, locum arrangements, and the workload of junior doctors, and make doctors aware of situations in which they are likely to commit errors.

Introduction

Prescribers are human, and therefore make mistakes. In the past, the response to such mistakes has been to focus on personal accountability, whatever the circumstances. However, the systems in which people work also contribute to errors. Findings of studies of industrial errors, and from the discipline of human psychology, have resulted in development of frameworks to analyse the causes of errors and to suggest solutions. Reason¹ developed one such framework, which has been applied to medical error² and is the theoretical basis behind our study (figure 1).

Errors made during drug prescription are the most common type of avoidable medication error, and are hence an important target for improvement.3, 4 In the UK, the Department of Health is committed to reducing by 40% the number of serious errors involving prescribed drugs, by 2005.⁵ Similar initiatives have been proposed in the USA.⁶ To achieve such a reduction in mistakes, we first need to understand the frequency and cause of errors. In this prospective pilot study in a UK hospital we have defined prescribing errors, measured their incidence,⁸ and aimed to understand their causes.