Why it matters
Every year, over 1.4 million patient safety incidents (events that cause or could cause harm to patients) are reported to NHS England. More than 20,000 are classed as serious incidents and until recently, all such incidents had to be reported and investigated, with the aim of finding out what factors contributed to the incident.
A common approach for investigations is called root cause analysis. This gives a framework for investigators to use in understanding what happened and why the incident occurred.
One criticism of root cause analyses is that they may not identify systemic issues within organisations across multiple incidents.
Our approach
We performed a content analysis of 126 investigation reports from a multi-site NHS trust over a three-year period between 2013 and 2015. This site is a large teaching hospital trust with over 10,000 staff looking after over one million patients every year. We used a structured framework to try to understand the organisational influences on serious incidents at an organisational level: the Human Factors Analysis and Classification System (HFACS). This framework considers both active failures and background conditions that could lead to an incident.
The investigation reports we examined described the background to the incident, a timeline of key events in the care of the patient, a breakdown of the service and care delivery problems identified by the investigators, the root causes, and the actions taken.
We used a HFACS framework to characterise the types of contributory factors identified by investigators in these reports, modifying it to account for the kinds of contributory factors we identified.
What we found
The two most common types of incidents were inpatient falls (12%) and delayed or missed diagnosis of other (non-cancer) condition (12%). Emergency medicine (18%), and obstetrics and gynaecology (15%) were the two specialties most commonly involved based on the reports.
Our modified HFACS framework had five levels (each with numerous sub-levels): extra-organisational factors, organisational factors, supervisory factors, preconditions for unsafe acts, and unsafe actions.
The most commonly identified level of contributory factor in the reports was unsafe actions, reported 282 times across 99 incidents. These included errors, meaning both unintentional slips and deliberate actions that were inappropriate for the situation. They also included violations such as poor documentation and delays in acting on results.
The next level, preconditions for unsafe acts, were reported 223 times across 91 incidents. This included miscommunication and environmental factors such as physical and technological factors. Supervisory factors were identified 73 times across 40 incidents, and organisational factors 115 times across 59 incidents.
The most frequently identified supervisory factor was inappropriate planning, leading to staff who were caring for patients being overloaded with work. Organisational factors included not having guidelines or standard operating procedures or having inadequate staffing and high caseloads.
Our analysis offers important insights into what investigators view as contributory factors to incidents, and the findings raise questions about why investigation teams identify certain contributory factors more than others. These findings are relevant for policy and practice, although they should not be understood as providing an objective account of the true causes of incidents or their relative frequencies. Instead, they provide significant insight into what investigators see as contributory factors to incidents that they describe in investigation reports.
We found an emphasis in investigation reports on human error, for example, relating to clinical decision making, but little engagement with why it occurs. This may suggest that too much focus is placed on the individual causes of incidents, rather than their systemic causes.
Another important emphasis in the reports was on environmental factors, such as poorly designed clinical spaces and technological problems. However, there was little mention of the extra-organisational factors (such as procurement practices or national standards) that might play a role. The identification of these factors is of crucial importance in appropriate allocation of responsibility across the healthcare system.
To improve serious incident investigations, we suggest the need for increased independence and professionalisation of investigators, wider involvement of specialists in human factors and the use of systems theory – which suggests that safety can only be appreciated when all the interactions between different components of a system are studied together – during investigations.
