Table 4.

Relationships between failure models and identified contributory factors

	Failure point (taken from the HTA)	Example of active failure	Type of task step	Likely contributing factors	Recovery step	Potential mitigation strategies
Slips and lapses	3.2–3.4	Failure to document prescription details appropriately.	Information entry and communication.	Cognitive burden; memory processing; workload and prioritisation; and support.	Nursing staff will not administer medication without a complete prescription.	Computerised physician order entry and standardised order sets.
	3.7 and 3.8	Failure to document times for administration.
	3.10	Failure to sign the prescription.	Information entry.
Rules-based mistakes	3.5.1–3.5.4	Failure to undertake pre-prescription checks (physiology, organ status, other meds and route).	Planning; information retrieval; and information interpretation.	Skills and knowledge; complexity; and verbal communication.	Pharmacist review of medication.	Computerised Decision Support Systems (CDSS).
	3.7	Select incorrect dosing frequency/times.	Selection; information retrieval; and information entry.	Skills and knowledge; complexity; verbal communication; and ambiguous information.	Nursing staff will not administer medication if frequency is incorrect.	Standardised order sets.
	3.5.4.2–3.5.4.4	Incorrect calculation; wrong final infusion volume/concentration; and wrong infusion rate.	Information retrieval; information entry; and calculation.	Cognitive burden; skills and knowledge; inexperience; verbal communication; ambiguous information; and divergent practice.	Nursing staff will not administer medication if infusion prescription is incorrect.	Organisationally standardised infusion concentrations and prescriptions.
Knowledge-based mistakes	3.1	Incorrect action taken based on faulty analysis of different drug dosing references.	Information retrieval; communication; and information interpretation.	Verbal communication; ambiguous information; skills and knowledge; and divergent practice.	Nursing staff will not administer medication if dosing reference is ambiguous.	Standardised formularies.
	3.5.1	Failure to take account of interactions (drug/disease), effects of fluid restriction, impact of route of administration and age/weight.	Information retrieval and information interpretation.	Verbal communication; ambiguous information; and skills and knowledge.	None.	CDSS.
	3.5.4.3	Wrong final infusion volume/concentration.	Information retrieval; information entry; and calculation.	Cognitive burden; ambiguous information; skills and knowledge; inexperience; and divergent practice.	Nursing staff will not administer medication if infusion prescription is incorrect.	Organisationally standardised infusion concentrations and prescriptions.
	3.9.2	Failure to identify monitoring conditions.	Planning; communication; and information entry.	Ambiguous information; skills and knowledge; and inexperience.	Nursing staff will challenge monitoring requirements.	CDSS.