Table 1

Classification of contributing factors according to the Eindhoven Classification Model22 23

Code	Subclass	Definition
Human failure (H)
Hex	External	Human failures originating beyond the control and responsibility of the investigating organisation.
HKK	Knowledge-based behaviour	The inability of an individual to apply his/her existing knowledge to a novel situation.
HRQ	Qualifications	An incorrect fit between an individual’s training or education and a particular task.
HRC	Coordination	A lack of task coordination within a healthcare team in an organisation.
HRV	Verification	The correct and complete assessment of a situation including related conditions of the patient and materials to be used before starting the intervention.
HRI	Intervention	Failures that result from faulty task planning and execution.
HRM	Monitoring	Monitoring a process or patient status.
HSS	Slips	Failure in performance of highly developed skills.
HST	Tripping	Failures in whole body movements. These errors are often referred to as ‘slipping, tripping, or falling’.
Organisational failure (O)
Oex	External	Failures at an organisational level beyond the control and responsibility of the investigating organisation.
OK	Transfer of knowledge	Failures resulting from inadequate measures taken to ensure that situational or domain-specific knowledge or information is transferred to all new or inexperienced staff.
OP	Protocols	Failures relating to the quality and availability of the protocols within the department (too complicated, inaccurate, unrealistic, absent or poorly presented).
OM	Management priorities	Internal management decisions in which safety is relegated to an inferior position when faced with conflicting demands or objectives. This is a conflict between production needs and safety.
OC	Culture	Failures resulting from a collective approach and its attendant modes of behaviour to risks in the investigating organisation.
Technical failure (T)
Tex	External	Technical failures beyond the control and responsibility of the investigating organisation.
TD	Design	Failures due to poor design of equipment, software, labels or forms.
TC	Construction	Correct design, which was not constructed properly or was set up incorrectly.
TM	Materials	Material defects.
Other
PRF	Patient-related factor	Failures related to patient characteristics or conditions, which are beyond the control of staff and influence treatment.
X	Other	Failures that cannot be classified in any other category.