Recurring concern

Failure to control confirmation bias in safety-critical decision-making

First to latest report 28 Aug 2020 — 14 Oct 2025

Reports that mention this concern
5
Times this concern has been raised
5
Stated actions linked to this concern
6

What this concern includes

Includes failures of controls specifically dedicated to recognising, challenging or mitigating confirmation bias in safety-critical clinical, emergency or custodial decision-making, including training, review mechanisms, professional-curiosity safeguards and assessment processes.

What is not included
  • Excludes generic training, professional-curiosity or decision-making deficiencies that are not explicitly linked to confirmation bias.
  • Excludes ordinary clinical errors or poor decisions where confirmation bias is not identified as the relevant unsafe condition.
  • Excludes generic information-sharing, staffing, governance or communication failures unless they directly undermine a dedicated confirmation-bias control.
  • Excludes unrelated prioritisation or triage failures where the reported problem is not bias affecting the safety-critical decision.

Reports and published responses 5 reports

See individual reports that have raised this concern, and the actions taken in response

  1. Inner South London

    AI-generated summary

    Paula Doreen Hughes · Prevention of Future Deaths report

    This summary was generated using AI from the published report. Please read the original report for the complete account.

    Report summary

    Paula Doreen Hughes was admitted to hospital after a fall and received paracetamol in excess of the recommended dose because paracetamol was prescribed alongside co-codamol. The overdose was not recognised until she had developed fulminant acute liver failure, and timely treatment was not provided. The principal concerns included preventing duplicate paracetamol prescriptions and administration, recognising and managing therapeutic excess, accurately assessing confusion, recording over-the-counter medicines, mitigating confirmation bias, and providing guidance for virtual patient reviews.

    Read the report on judiciary.uk

    Source evidence

    How this individual concern was interpreted

    PFD Monitor created a concise, searchable interpretation from the report wording shown below.

    PFD Monitor interpretation

    Lack of robust mechanisms to mitigate confirmation bias and encourage professional curiosity

    Wider context from the report

    “5. Trust approach to mitigating against confirmation bias and encouraging professional curiosity (LGT) Confirmation bias and a lack of professional curiosity were significant features in Mrs Hughes’ being administered two paracetamol containing drugs at the same time and in not investigating whether she had received a therapeutic excess and suffered consequential harm. I have found that the Trust does not have robust mechanism for mitigating against confirmation bias and encouraging professional curiosity. ”

    Source location

    Paula Doreen Hughes · Prevention of Future Deaths report
    Page 4 · concerns

    Open source report

    Source evidence

    How this respondent action was interpreted

    PFD Monitor created a concise, searchable interpretation from the published response wording shown below.

    PFD Monitor interpretation

    Share learning from the case about confirmation bias and professional curiosity through Grand Round and medical-student teaching.

    Verbatim wording from the response

    “Learning from patient safety incidents is embedded at LGT at a local (weekly incident teaching) and at an organisational level. The October 2025 Patient Safety Group has presented this case for discussion and learning specifically regarding whether confirmation bias played a role in Ms Hughes’ care. This case will also be shared in Grand Round and with medical students in 2025/26.”

    Source location

    Response from Lewisham and Greenwich NHS Trust
    Page 5 · response
    Published 19 December 2025

    Open published response

    Source evidence

    How this respondent action was interpreted

    PFD Monitor created a concise, searchable interpretation from the published response wording shown below.

    PFD Monitor interpretation

    Present the case for patient-safety discussion and learning about confirmation bias.

    Verbatim wording from the response

    “Learning from patient safety incidents is embedded at LGT at a local (weekly incident teaching) and at an organisational level. The October 2025 Patient Safety Group has presented this case for discussion and learning specifically regarding whether confirmation bias played a role in Ms Hughes’ care. This case will also be shared in Grand Round and with medical students in 2025/26.”

    Source location

    Response from Lewisham and Greenwich NHS Trust
    Page 5 · response
    Published 19 December 2025

    Open published response

  2. Manchester West

    AI-generated summary

    Craig Brendon SPIBY · Prevention of Future Deaths report

    This summary was generated using AI from the published report. Please read the original report for the complete account.

    Report summary

    Craig Brendon SPIBY, who had a condition that made him susceptible to choking, died on 13 July 2024 after choking on a sandwich while eating lunch unsupervised at an assisted living facility. The principal concerns were inconsistent understanding and use of monitoring and supervision requirements, inadequate clarity in care-plan terminology, insufficient professional curiosity when he was believed to be asleep, limited confidence in choking-related first aid, and a lack of training addressing confirmation bias.

    Read the report on judiciary.uk

    Source evidence

    How this individual concern was interpreted

    PFD Monitor created a concise, searchable interpretation from the report wording shown below.

    PFD Monitor interpretation

    Absence of training to guard against confirmation bias in assessing enduring choking risk

    Wider context from the report

    “The deceased had an enduring risk of choking, especially at mealtimes, and was the subject of a Care and Support Plan; Bad Day Support Plan; Good Day Consistency and bespoke Eating and Drinking Guidelines that had been updated in 2018. The Care and Support plan made clear that at mealtimes in particular, the deceased ought to be ‘monitored’. The Speech and Language Therapy guidance made clear that at mealtimes the deceased was to be ‘supervised’. Managers gave evidence that their definition of ‘monitoring’ and ‘supervising’ was an expectation that the deceased would be kept in ‘line of sight’ at all times. Care workers gave evidence that they were expected only to ‘monitor’ the deceased – which had the consequence of meaning they felt it appropriate to leave the deceased unsupervised but within earshot, in differing rooms of the care facility for short period of time. Care workers also gave evidence to the effect that improvement to first aid training when dealing with a choking or aspiration emergency would be beneficial. It follows that the following matters of specific concern arise: 1. A lack of understanding and/or training as to the specific requirements and expectations as to the role of care staff when supervising/monitoring a service user. 2. The confusion that arises in the existence differing language that applies in Care Plans and Guidance with no corresponding definition of the terms used. 3. How and why staff having assumed the deceased to have fallen asleep at a mealtime after a period of absence from the room, did not use more professional curiosity to evaluate whether such an assumption was correct or safe. 4. The lack of confidence expressed by staff in the emergency first aid training provided when responding in a choking case. 5. An absence of training to guard against confirmation bias with long term service users who have enduring high risk of choking, but with no actual previously recorded episodes of such events. ”

    Source location

    Craig Brendon SPIBY · Prevention of Future Deaths report
    Page 2 · concerns

    Open source report

    Source evidence

    How this respondent action was interpreted

    PFD Monitor created a concise, searchable interpretation from the published response wording shown below.

    PFD Monitor interpretation

    Implement an electronic Read and Sign record requiring new staff to familiarise themselves with SALT guidelines immediately.

    Verbatim wording from the response

    “Craig was diagnosed with Phelan McDermid Syndrome. This syndrome increases the risk of choking and aspiration. There had been no reported episodes of choking for many years, but the risk remained consistent. To address this, we have included a reminder of not becoming complacent within the toolbox talk described above and in addition to the SALT guidelines, which we currently complete, we have implemented an electronic ‘Read and Sign’ record. This will ensure that new staff members are required to familiarise themselves immediately.”

    Source location

    Response from Bolton Cares
    Page 4 · response
    Published 27 December 2024

    Open published response

    Source evidence

    How this respondent action was interpreted

    PFD Monitor created a concise, searchable interpretation from the published response wording shown below.

    PFD Monitor interpretation

    Add SALT guidelines to standard bi-monthly team meeting agendas to reinforce ongoing awareness of choking risk.

    Verbatim wording from the response

    “We have also included ‘SALT guidelines’ on our standard Team Meeting agendas. These team meetings take place every two months and by including this on the agenda we are reminding staff team that the guidelines are in place and despite there being no incidents, the risk remains the same.”

    Source location

    Response from Bolton Cares
    Page 5 · response
    Published 27 December 2024

    Open published response

  3. South Yorkshire (Western)

    AI-generated summary

    James Philliskirk · Prevention of Future Deaths report

    This summary was generated using AI from the published report. Please read the original report for the complete account.

    Report summary

    James Philliskirk was assessed twice in A&E after becoming unwell following a recent chickenpox infection and was sent home on both occasions. He developed sepsis and died at home on 13 May 2022. Concerns included failures to escalate to senior staff, unclear guidance on chickenpox reinfection and secondary complications, confirmation bias, inadequate assessment of skin lesions, and insufficient weight given to GP referral outside the usual route.

    Read the report on judiciary.uk

    Source evidence

    How this individual concern was interpreted

    PFD Monitor created a concise, searchable interpretation from the report wording shown below.

    PFD Monitor interpretation

    Confirmation bias affecting clinical reviews

    Wider context from the report

    “3. Confirmation bias affecting clinical reviews ”

    Source location

    James Philliskirk · Prevention of Future Deaths report
    Page 2 · concerns

    Open source report

    Source evidence

    How this respondent action was interpreted

    PFD Monitor created a concise, searchable interpretation from the published response wording shown below.

    PFD Monitor interpretation

    Deliver the ‘Keeping Safe in ED’ induction module covering human factors, confirmation bias, chickenpox learning and listening to parents.

    Verbatim wording from the response

    “The induction training for junior doctors now includes a module called ‘Keeping Safe in ED’. In August 2022 this was added to the induction to discuss human factor principles (including confirmation bias) and the importance of listening to parents.”

    Source location

    Response from Sheffield Children's NHS Foundation Trust 2
    Page 2 · response
    Published 18 October 2023

    Open published response

    Source evidence

    How this respondent action was interpreted

    PFD Monitor created a concise, searchable interpretation from the published response wording shown below.

    PFD Monitor interpretation

    Raise staff awareness of human factors by developing educational videos for current and future Trust staff.

    Verbatim wording from the response

    “In addition, throughout the Trust, work is being done to raise awareness of human factors, their role in decision making and how errors can occur. Funding has been acquired to make educational videos highlighting this vitally important area. They will be used to support the education of all staff groups now and future cohorts across the Trust as well as in the ED.”

    Source location

    Response from Sheffield Children's NHS Foundation Trust 2
    Page 2 · response
    Published 18 October 2023

    Open published response

  4. South Yorkshire (Eastern)

    AI-generated summary

    Clay Daniel Wanckiewicz · Prevention of Future Deaths report

    This summary was generated using AI from the published report. Please read the original report for the complete account.

    Report summary

    Clay Daniel Wanckiewicz was born in very poor condition following failed forceps delivery and caesarean section complicated by a deeply impacted head, and died at 22 minutes of age from skull fractures. The principal concerns were confirmation bias, insufficiently open-minded assessment of the overall clinical picture, inadequate staff training and a continuing risk that similar situations could place mothers and babies at risk.

    Read the report on judiciary.uk

    Source evidence

    How this individual concern was interpreted

    PFD Monitor created a concise, searchable interpretation from the report wording shown below.

    PFD Monitor interpretation

    Failure to prioritise relevant staff for confirmation bias training

    Wider context from the report

    “(1) Failure of members of staff to understand the concept of confirmation bias. (2) A reluctance on the part of staff to accept situations of confirmation bias and be open to altering practices. (3) I am not satisfied the Newsletters had been considered and digested by all staff. (4) The training program in place is delivered over a 12-month period thus many staff members will not have had that training and there is a risk that confirmation bias situations will continue placing mothers and their babies at risk. Furthermore, some staff members who were involved in Clay’s management were not prioritised to have that training. These are the reasons for my belief that there continues to be a risk. ”

    Source location

    Clay Daniel Wanckiewicz · Prevention of Future Deaths report
    Page 3 · concerns

    Open source report

  5. Lincolnshire

    AI-generated summary

    Carlington Maurice Spencer · Prevention of Future Deaths report

    This summary was generated using AI from the published report. Please read the original report for the complete account.

    Report summary

    Carlington Maurice Spencer, a detainee at Morton Hall IRC, suffered a right middle cerebral artery infarction after being found unwell and was later confirmed deceased on 3 October 2017. The report identifies concerns about confirmation bias relating to presumed drug use, inadequate monitoring and record keeping, poor communication and escalation between discipline and healthcare staff, failures to recognise stroke symptoms, and delays in emergency treatment.

    Read the report on judiciary.uk

    Source evidence

    How this individual concern was interpreted

    PFD Monitor created a concise, searchable interpretation from the report wording shown below.

    PFD Monitor interpretation

    Lack of training on confirmation bias affecting staff decision making

    Wider context from the report

    “4. Training is needed to enable staff to appreciate the potential for their decision making to be affected by "confirmation bias" in addition to the need for diversity awareness training when dealing with detainees of Afro-Caribbean heritage; ”

    Source location

    Carlington Maurice Spencer · Prevention of Future Deaths report
    Page 5 · concerns

    Open source report

Actions and positions describe what organisations say in published responses. Implementation is not independently verified.

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Data last updated 7 September 2026