Table 3.

Number of HTA step discrepancies coded with each error mode, and an example of each

HTA step	Error modea	Number of reports coded		Summary of example incident report (reported degree of harm)
		All levels of harm	Death and severe harm
Step 1 – find the right guideline(s)	A1	5	0	NHS Injectable Medicines Guide website offline, therefore administration of intravenous metoprolol delayed (No harm)
	R1	30	1	Local unfractionated heparin intravenous infusion guideline not located on hospital intranet, and ward’s printed copy lost. Infusion rate should have been adjusted at 09:30 h, but was not reviewed until 19:00 h (No harm)
	R2	79	3	Elderly patient with infective exacerbation of bronchiectasis prescribed intravenous tobramycin 10 mg/kg/day instead of 3 mg/kg/day, as the cystic fibrosis guideline was inappropriately used. Patient developed acute kidney injury and died (Death)
	R3	41	0	Intravenous omeprazole infusion administered at 0.6 mg/h instead of 8 mg/h. Local guideline should have been used to clarify the infusion rate in addition to the NHS Injectable Medicines Guide (No harm)
	R4	73	3	Paediatric insulin infusion prescribed without checking local guidelines. Prescribed infusion rate was 10 times too high and was administered for 1 h, leading to hypoglycaemia (Severe)
	R5	72	2	Patient not prescribed venous thromboembolism prophylaxis on discharge for 28 days following cancer-related surgery, as no local guideline for specific type of surgery. Patient readmitted with deep vein thrombosis after 7 days (Moderate)
Step 2 – find all relevant information within the guideline(s)b	R1	1	0	Information on contraindication of morphine in severe headache not found in the Joint Royal Colleges Ambulance Liaison Committee guideline, therefore inappropriately administered (No harm)
	R2	68	1	Prescribed nitrofurantoin to a first-trimester pregnant patient (contraindicated), as followed ‘non-pregnant’ section of the urinary tract infection guidelines (No harm)
	R3	20	0	Intravenous phenytoin infusion administered without an inline filter as this advice was not noticed in the NHS Injectable Medicines Guide (No harm)
	R5	77	3	Patient with poor renal function prescribed gentamicin for sepsis. Local guidelines advised obtaining advice from a microbiologist in this situation, but this advice was unavailable at the time (03:00 h). Subsequent gentamicin plasma levels were high (Low)
Step 3 – read and correctly use all relevant informationc	A1	1	0	Amiodarone infusion administered 2 h late due to discussion between nursing staff around the meaning of information provided in the NHS Injectable Medicines Guide (Low)
	R1	33	0	Labetalol intravenous infusion administered several hours late as nursing staff could not understand NHS Injectable Medicines Guide advice. Eventually administered in accordance with colleagues’ advice (No harm)
	R2	135	4	Child prescribed 150 mg of oral cefalexin instead of 75 mg, due to misreading of the British National Formulary (No harm)
	R3	3	0	Psychiatrist recommended increasing a patient’s zuclopenthixol decanoate depot injection from 600 mg to 1 g every 2 weeks. Pharmacist used British National Formulary and Summary of Product Characteristics to confirm this was within the maximum monthly dose, but did not notice that the maximum single dose should be 600 mg. Error detected after patient discharge, leading to community review of treatment options (Low)
	R4	4	0	Morphine and codeine prescribed for a palliative care patient with severe renal impairment. Online palliative care guideline had been used but prescriber did not seek relevant information on prescribing these drugs in renal impairment (No harm)

^aErrors modes: A1 = operation took too long; R1 = information not obtained; R2 = wrong information obtained; R3 = incomplete information obtained; R4 = information not sought; R5 = information not available

^bNo HTA step 2 discrepancies were coded with error mode R4

^cError mode R5 was not applicable to HTA step 3

HTA hierarchical task analysis, NHS National Health Service