Table 1 Definitions

Opportunity for error

The number of opportunities for error (OE) was the denominator used to determine the MAE rate. An OE was defined as any dose that was prepared and administered to the patient and could be determined as being correct or incorrect by the researcher, or a dose that was due for administration but omitted in error [16]. An administered drug was defined as either the patient consuming the prepared medication or the prepared medication being left by the patient’s bedside for self-administration [16]. Medication doses that were administered unsuccessfully due to the patient being unable to take the dose or subsequent refusal were also considered OEs if the researcher could determine preparation and attempted administration as being correct or incorrect. Each dose was considered to be one OE.

Medication administration error

Medication administration errors (MAE) were defined as any deviation or omission from the medication order as stated on the patient’s drug chart [16]. An omission was defined as a dose of medication that had not been administered by the time of the next scheduled dose. This included omission of a dose because the medication was not available on the ward as well as unintentional omissions. Doses omitted according to a doctor’s instructions, or if the patient was not on the ward or refused the medication, were not considered to be OEs. Doses omitted as a result of a nurse’s clinical judgement were also not considered OEs. Administration processes that did not adhere to local hospital policy were not considered MAEs; for example a dose not administered within two hours of the time for which it was prescribed was not considered an MAE if it was otherwise correct. Errors prevented by the observer were included as MAEs although errors prevented by other healthcare professionals working within their usual roles were not.

Documentation discrepancies

Discrepancies in documentation (DD) occurred when the documented details of dose administration or omission were different to what happened in practice as observed by the researcher [16]. Documentation was considered for all medication doses due, including omissions.