An investigation into the effect of the decision-making process and human factors in prescribing errors within an inpatient mental health setting

  • Hilary Frances Scott

Student thesis: Doctoral Thesis


Research on the prevalence and causes of prescribing errors has concentrated on the acute sector, with little published in relation to mental health. Studies into dual process theory in healthcare have tended to concentrate on its role in diagnosis and no studies have looked at whether there is a relationship between thinking style and prescribing errors.
The purpose of this research was to investigate the effect of rational and experiential thinking and other human factors on the occurrence of prescribing errors.

The research was carried out in one mental health trust and consisted of four interrelated elements. Firstly, a prospective, quantitative study investigated the prevalence and nature of prescribing errors. Secondly, semi-structured qualitative interviews were undertaken with a sample of clinicians who had made errors to explore the causes and factors contributing to them. Thirdly, prescribers’ decision-making characteristics were profiled using validated scales and the relationship with prescribing errors explored. Finally, the impact of an educational intervention about clinical decision making on prescribing errors was measured.

Key Findings
The overall error rate was 4.6%, with significantly higher rates of prescribing errors observed at those stages in the patient’s journey involving transitions of care, (on admission 6.2%; discharge 7.7%), and for early career prescribers, with foundation, core and GP trainees having the highest error rates (≥ 5.6%). A weak, but significant, inverse relationship was found between experience and error rates. Nearly two-thirds of errors (61.1%) were intercepted before any dose was administered and few errors were considered to be potentially severe.
Rule-based mistakes were the most common, and all prescribers reported that they were unaware of their error(s) until contacted as part of the research. Factors cited by interview participants were generally similar to those found in previous studies, however some factors raised had not been identified in previous research. Electronic prescribing is more commonly used in acute trusts, particularly teaching hospitals; as a result, junior doctors may enter a psychiatry rotation with little or no experience of using paper drug charts. Furthermore, despite the recommendation of the EQUIP study for a standard national drug chart across the NHS, individual trusts continue to use drug charts that vary widely which can contribute to errors due to both design and lack of familiarity. Lack of access to information about a patient’s primary care medication regimen, compounded by the tendency of community pharmacists to label the secondary, outer container of medicines such as inhalers, also contributed to prescribing errors. Access to the Summary Care Record for all prescribers would help prevent such errors, particularly out-of-hours, when other resources such as the GP surgery and hospital pharmacy team are not available.
Participants generally demonstrated a preference for rational thinking and a tendency to organise, abstract and evaluate information. No statistically significant relationship was found between performance on any of the decision-making scales used and prescribing errors. An educational intervention on clinical decision making did not result in a reduction in prescribing errors.

It is likely that multifaceted interventions are needed to improve the quality of prescribing and reduce errors. These should be designed to target both the rational and experiential processing preferences of individuals. An educational approach which addresses the theory of clinical decision making, error-prone types of prescribing, and systems to support prescribing reduce errors, should be accompanied by on-going feedback on prescribing errors to facilitate learning. Clinical and educational tutors have a crucial role to play in reinforcing the importance of prescribing as a clinical task and strategies to minimise errors.
Date of AwardSept 2018
Original languageEnglish
Awarding Institution
  • University of Portsmouth
SponsorsEssex Partnership University NHS Foundation Trust
SupervisorDavid Brown (Supervisor) & Helena Herrera (Supervisor)

Cite this