Table 1

Summary of article characteristics

Citation	Type of study	Setting	Type of medication studied	Type of numerator	Type of denominator	How were data obtained	Types of errors collected
ADE, adverse drug event; CPOE, computerised physician order entry; ICU, Intensive care unit; MAR, medication administration record; MedMARx, United States Pharmacopeia database designed to reduce medication errors in hospitals; MER: medication errors reporting programme submitted to United States Pharmacopeia; TPN, total parenteral nutrition; VLBW, very low birth weight.
*ADEs are defined as having the potential to produce significant injury, includes errors detected before drug administration as well as errors that did not produce significant adverse consequences, excludes errors that were identified and corrected before the medication was entered into MAR.
†ICD9, International Classification of Disease, 9th edition. Public Health Service and Health Care Financing Administration. International classification of diseases, 9th revision, clinical modification. Vols 1, 2, and 3; eighth edition. Washington, DC: Public Health Service; 1997.
‡Code 995.2: adverse effect/allergic reaction/hypersensitivity/idiosyncrasy of drug, medicinal and biological substance (due) to correct medicinal substance properly administered.
Simpson et al²³	Interventional	ICU patients only	All types		Patient days	Incident/error reports	All types
Petridou et al²⁵	Retrospective review without controls	Clinic or outpatient	Vaccines	Medication errors	Time period (2 years)	Incident/error reports	All types
Cimino et al²⁸	Interventional	ICU patients only	All types	Adverse drug events and medication errors	Manual medication orders	Chart reviews	All types
Butte et al⁴¹	Cohort		Immunisations	Medication errors	Manual medication orders and patients	Chart reviews	All types
Marino et al⁴³	Cohort	Inpatient	All types	Medication errors	Manual medication orders and patient days	Chart reviews	All types
Cote et al⁴⁵		Inpatient and outpatient	Sedatives for procedures	Medication errors	Manual error reports	Incident/error reports, solicited case reports	All types
Upperman et al⁴⁷	Interventional	Inpatient	All types	Adverse drug events	Per 1000 doses dispensed	Incident/error reports	All types
Slonim et al⁵⁰	Retrospective review without controls	Inpatient	All types	ICD9 code 995.2!	Admissions	Administrative data (ICD9 codes)	All types
Cowley et al⁴⁸	Incident report/case series review	Inpatient	All types	Medication errors	Computerised error reports	Incident/error reports from MER and MedMARx	All types and administering
Potts et al³⁰	Interventional	ICU patients only	All types	Adverse drug events and medication errors	Manual medication orders	Chart reviews	All types and prescribing
Holdsworth et al³⁵	Retrospective chart reviews and staff interviews	Inpatient	All types	Preventable ADEsas determined by authors and potential ADEs	Patient days, admissions and medical record evidence of ADE*: excluded errors corrected before medication put into MAR	Chart reviews and interviews	All types, prescribing and dispensing
Sangtawesin et al³¹	Retrospective review without controls	Inpatient	All types	Medication errors	Admissions	Incident/error reports	All types, prescribing, dispensing and administering
Frey et al³⁸	Incident report/case series review	ICU patients only	All types	Medication errors	Manual error reports	Incident/error reports	All types, prescribing, dispensing, administering and MAR/documentation
Kaushal et al⁴²	Cohort	Inpatient	All types	ADEs and medication errors	Manual medication orders, patient days and admissions	Chart reviews	All types, prescribing, dispensing, administering, monitoring patient for effect and MAR/documentation
Derrough and Kitchin³⁷	Incident report/case series review	Mix	Vaccines	Inadvertent vaccine administration	Prospective inquiries of inadvertent admission of vaccines: calls by providers to pharmaceutical company information service	Incident/error reports	Administering
Li et al⁴⁴	Cross sectional	Home	Paracetamol and ibuprofen	Medication errors	Patients ⩽10 receiving paracetamol or ibuprofen at home in past 24 hours	Survey to parents	Administering
Losek⁴⁶	Retrospective review without controls	Emergency department	Paracetamol administered by emergency department staff	Medication errors	Patients	Chart reviews	Administering
Feikema et al⁵¹	Cross sectional	Clinic or outpatient	Vaccines	Extra immunisations	Patients	Chart reviews from National Immunisation Survey screenings	Administering
Goldman and Scolnik⁵²	Cross sectional parental interview	Home	Paracetamol administered by parents at home	Medication errors	Patients	Interviews	Administering
McErlean et al⁵³	Cross sectional parental interview	Home	Antipyretic drugs administered by parent at home	Medication errors	Patients	Interviews	Administering
Parshuram et al³²	Prospective observational	ICU patients only	Morphine infusion	Discrepancies between ordered and measured concentrations	Number of infusions	Liquid chromatography	Dispensing
Cable and Craft²⁶	Retrospective review without controls	Inpatient	All types	Disagreement of Cardex with order	Manual medication orders	Chart reviews	MAR/documentation
Lehmann et al²⁷	Interventional	ICU patients only	TPN	Medication errors	Manual medication orders (TPN)	Order review	Prescribing
Cordero et al²⁹	Interventional	ICU patients only	Gentamicin	Medication errors	VLBW infants born consecutively 6 months before CPOE receiving drug	Chart reviews and medical records	Prescribing
Lesar³⁶	Incident report/case series review	Inpatient	All types	Medication errors	Computerised error reports, patient days and admissions identified by pharmacists and entered into relational database	Incident/error reports	Prescribing
Farrar et al⁴⁹	Interventional study	Inpatient	All types	Medication errors	Computerised medication orders	Chart reviews	Prescribing
Fontan et al³⁴	Cohort	Inpatient	All types	Medication errors	Manual medication orders and computerised medication orders	Chart reviews	Prescribing and administering
Kozer et al³⁹	Retrospective review without controls	Emergency department	All types	Medication errors	Manual medication orders	Chart reviews	Prescribing and administering
Pichon et al⁴⁰	Retrospective review with controls	Inpatient	All types	Medication errors	Manual medication orders	Chart reviews	Prescribing and MAR/Documentation
France et al²⁴	Incident report/case series review	Inpatient	Chemotherapy only	Medication errors	Computerised error reports	Incident/error reports	Prescribing, dispensing, administering and MAR/documentation
King et al³³	Interventional	Inpatient	All types	Adverse drug events and medication errors	Manual error reports	Incident/error reports	Prescribing, dispensing, administering and MAR/documentation