Explanation of causal factors categories
| Main category | Subcategory | Code | Description | |
| Latent conditions | ||||
| Technical | Design | TD | Failures due to poor design of equipment, software, labels or forms | |
| Construction | TC | Correct design, which was not constructed properly or was set up incorrectly | ||
| Materials | TM | Material defects | ||
| External | T-ex | Technical failures beyond the control and responsibility of the investigating organisation | ||
| Organisational | Transfer of knowledge | OK | Failures resulting from inadequate measures taken to ensure that situational or domain-specific knowledge or information is transferred to all new or inexperienced staff | |
| Protocols | OP | Failures relating to the quality and availability of the protocols within the department (too complicated, inaccurate, unrealistic, absent or poorly presented) | ||
| Management priorities | OM | 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. Example: decisions that are made about staffing levels | ||
| Culture | OC | Failures resulting from a collective approach and its attendant modes of behaviour to risks in the investigating organisation | ||
| External | O-ex | Failures at an organisational level beyond the control and responsibility of the investigating organisation | ||
| Active errors | ||||
| Human | Knowledge-based behaviour | Knowledge-based behaviour | HKK | The inability of an individual to apply his/her existing knowledge to a novel situation |
| Rule-based behaviour | Qualifications | HRQ | An incorrect fit between an individuals training or education and a particular task | |
| Coordination | HRC | A lack of task coordination within a healthcare team in an organisation. Example: an essential task not being performed because everyone thought that someone else had completed the task | ||
| Verification | HRV | The correct and complete assessment of a situation including related conditions of the patient and materials to be used before starting the intervention | ||
| Intervention | HRI | Failures that result from faulty task planning and execution. Example: washing red cells by the same protocol as platelets | ||
| Monitoring | HRM | Monitoring a process or patient status. Example: a trained technologist operating an automated instrument and not realising that a pipette that dispenses reagents is clogged | ||
| Skill-based behaviour | Slips | HSS | Failures in performance of highly developed skills. Example: a computer entry error | |
| Tripping | HST | Failures in whole body movements. These errors are often referred to as “slipping, tripping or falling”. Examples: a blood bag slipping out of one's hands and breaking or tripping over a loose tile on the floor | ||
| External | H-ex | Human failures originating beyond the control and responsibility of the investigating organisation | ||
| Violations | V | Failures by deliberate deviations from rules or procedures | ||
| Other factors | ||||
| Patient related | Patient-related factor | PRF | Failures related to patient characteristics or conditions, which are beyond the control of staff and influence treatment. Example: communicative skills, treatment compliance | |
| Other | Unclassifiable | X | Failures that cannot be classified in any other category—eg, complication, abstain policy, rare disease | |
Descriptions (except for “violations”) are derived from Van Vuuren et al12 and Van der Schaaf and Habraken.13