Why Fatigue of NHS Staff Matters and the Risk it Poses to Patient Safety

Fatigue within the NHS presents a significant risk to patient safety, yet in healthcare its consequences remain largely unrecognised despite the increasing demands on NHS workforces.

In this article, we will discuss the risks and impact that NHS staff fatigue can have on patient safety, and consider the findings outlined in The Health Services Safety Investigations Body’s (HSSIB) recently published report on the matter.

What is Fatigue?

The HSSIB investigation report acknowledges that fatigue in healthcare is often misunderstood, and viewed primarily as a wellbeing concern rather than a critical patient or staff safety risk. This is evidenced by the lack of a healthcare-specific definition of fatigue. For the purpose of the investigation, the following definition of fatigue was therefore adopted from an alternative safety-critical industry:

“A physiological state of reduced mental or physical performance capability resulting from sleep loss, extended wakefulness, circadian phase [the natural daily internal body clock], and or workload (mental and or physical activity) that can impair a person’s alertness and ability to perform safety related operational duties”. 

Adopting the above definition, the investigation found that staff fatigue does contribute both directly and indirectly to patient harm. However, inconsistent understandings of fatigue and the impact it can have on patient (and staff) safety prevented fatigue risks from being understood, reported, and addressed. HSSIB therefore made a safety recommendation [1] within their report that a statement defining fatigue for healthcare staff needed to be developed.

The Prevalence of Fatigue

The HSSIB investigation highlighted that staff fatigue typically appears to arise as a result of organisational factors, including high workloads, long shifts, insufficient rest facilities and inadequate rest breaks during and between shifts.

The 2024 NHS Staff survey conducted in England found that, of staff working in acute hospital settings, approximately 40% reported feeling worn out by the end of their working day/shift either ‘always’ or ‘often’, and 20% of staff reported ‘always’ or ‘often’ feeling that every waking hour was tiring for them.

More recently, in a survey of doctors conducted by the Medical Defence Union, 22% confirmed that they felt sleep deprived on a daily basis, with an additional 19% feeling sleep deprived on a weekly basis. Perhaps of even more concern is the fact that 35% declared tiredness had negatively impacted their ability to treat patients, with 34% saying that it might have contributed.

In order to address the seemingly prevalent issue of NHS staff fatigue, and thereby minimise the risk posed to patient safety, HSSIB proposes that research to measure and assess the impact of staff fatigue on staff and patient safety should be prioritised. This would help organisations assess and understand the risks associated with staff fatigue, and to monitor and manage its risks.

The Risks of Fatigue

A patient safety incident refers to any unintended or unexpected events which could have, or did, lead to harm for one or more patients receiving healthcare. Accurate recording of these incidents is crucial in aiding the NHS to improve care received by patients and certain patient safety incidents evidence the negative impact of NHS staff fatigue.

One NHS Trust who spoke to HSSIB described a patient safety incident involving an individual who was administered the incorrect chemotherapy infusion. Both members of staff responsible for checking the infusion were almost 9 hours into their 12.5-hour shift. They reported having had inadequate sleep between shifts, the inability to take a sufficient break during their shift due to high workloads and not having had the right combination of skilled staff on shift at the time. The internal investigation carried out by the Trust acknowledged that staff fatigue was likely to have been a factor that led to this incident occurring.

[2] Studies carried out into the risks of long shift patterns document the correlation between working longer shifts of 12 hours or more, with a higher risk of accidents or injuries, when compared to shorter, 8-hour shifts. Despite this, staff interviewed by HSSIB described frequently working shifts lasting over 12 hours, together with additional on-call shifts. On-call shifts were reported to typically be 12 hours long, and staff reported these often commencing immediately after their daytime shift, resulting in some staff working for 24-hours with little to no breaks.

NHS staff fatigue can therefore act as a contributory factor in patient safety incidents. In order to address these risks, the HSSIB report recommends that NHS England / the Department of Health and Social Care identifies and reviews any current processes that may capture staff fatigue related data. This data will help inform the development of any future strategy and action to address staff fatigue risk, and its impact on patient safety.

Legal Claims

We hope that the safety recommendations proposed by HSSIB are acknowledged by the NHS and steps are taken to begin promoting a better understanding of fatigue so that staff and organisations alike can work towards reducing the identified risk fatigue of NHS staff is having on patient safety.

If you have suffered harm as a result of a patient safety incident and want to discuss whether you may have a legal claim, please do not hesitate to contact our supportive and friendly team for a no obligation discussion.

[1] Health Services Safety Investigations Body Investigation Report: The impact of staff fatigue on patient safety 24/04/2025, Safety recommendation R/2025/062

[2] British Medical Association (2018) Fatigue and sleep deprivation – the impact of different working patterns on doctors patterns on doctors.