Methodology

Three main methodological considerations were identified and are discussed: (1) method of data collection, (2) MAE definition, denominator and subcategories, and (3) identifying the core tasks and defence barriers associated with medication administration

2.4.1 Method of data collection

The primary outcome measure of interest was the MAE rate; MAE rates can be measured using direct observation, chart review, and/or self-report. Direct observation was chosen as it is a valid and reliable method that is also widely considered to be the gold standard for collecting MAE data (Allan & Barker, 1990; Dean & Barber, 1999). This method also allowed other quality measures to be collected at the same time by the researcher (MM) who had previous experience in observing drug rounds for another study (Franklin et al., 2007).

However, there was a risk that the observer may influence the individual’s behaviour during the study. The largely unpredictable nature of the observer-effect on different individuals being observed is a problem that can be difficult to measure. Dean and Barber (2001) investigated the validity and reliability of observational method for studying MAEs in two wards of an acute NHS hospital. Overall, findings from Dean and Barber’s (2001) study suggest MAE rates were not significantly affected when a discreet, non-judgemental, and tactful observational approach used; this corroborated findings from an earlier study by Barker and McConnell (1962). Consequently, this was the approach that was used in the current study by the observer to minimise the risk of data contamination from potential observer-effects. In addition, the researcher was introduced to all the nursing staff prior to the start of the study and piloted data collection on the same ward to enable nurses to become familiar with the presence of an observer. The researcher also made every effort to be as unobtrusive as possible and encouraged nurses to feed back about their experience of being observed.

2.4.2 MAE definition, denominator, and MAE subcategories

An MAE was defined by Allan and Barker(1990) as any dose of medication administered (or omitted) that deviates from the patient’s medication order. This American hospital-based definition was used in the current study as it was specific to the medication administration process, was clear about the inclusion of dose omissions as an MAE, and has been widely used in MAE studies including in the UK, thus allowing relevant comparisons with previous research.

The associated MAE subcategories by Allan and Barker (1990) are listed in table 2.1.

Considerations for inclusion or exclusion of each MAE subcategory are summarised; these were largely based on a previous study that adapted Allan and Barker’s MAE subcategories and were considered more operational for use in UK hospital settings (Franklin et al., 2007). The MAE subcategories were mutually exclusive; only one MAE subcategory could be associated with each dose.

In the current study, ‘administration’ was taken to include leaving a dose at a patient’s bedside for self-administration and pharmacists’ written endorsements to clarify prescribers’

medication order were considered part of the medication order (Franklin et al., 2007). In circumstances where the medication order in an inpatient drug chart cross-referenced medication orders on a separate sheet, for example, a multiple resistant Staphylococcus aureus (MRSA) protocol, it was the separate sheet that was considered to be the medication order and not any cross-references in the drug chart.

To determine the MAE rate, the denominator used in the current study was the total number of OEs, defined by Allan and Barker (1990) as the sum of all doses given plus all doses omitted (ordered, but not given). The overall MAE rate was calculated as the number of MAEs divided by the total number of OEs, multiplied by 100 (Allan & Barker, 1990; Franklin et al., 2007).

Table 2.1 Medication administration error (MAE) subcategories used in the current study.

MAE subcategory

Description by Allan and Barker (1990) (developed for use in American hospital

setting)

Inclusion, exclusion, and/or elaboration of definitions used in the current study for an MAE (based on Franklin et al

2007) Omission An omission error takes place when a

patient has not received his or her medication by the time the next dose is due.

Included. A dose of medication that has not been administered by the time of the next scheduled dose (does not include doses omitted according to doctor’s instructions, nurse’s clinical judgement, or if patient not on ward).

Omissions due to drug not being available were differentiated from other types of omissions.

Wrong dose A wrong dose error typically occurs when the patient receives an amount of medicine that is greater than or less than the amount ordered.

Included. The administration of the correct drug by the correct route but in a quantity that was not that prescribed (includes administration of incorrect number of dose units, selection of the wrong strength and the measurement of an incorrect volume of an oral liquid (+/- one graduation mark from the intended volume required, or more drops than that was required).

Unordered drug An unordered drug error occurs when a patient receives a medication for which the physician did not write an order. This includes those that result when a nurse switches medications for two patients; each patient is the victim of an unordered drug error (as well as an omission)

Included. The administration of a drug that was not prescribed at all for the patient concerned (classified as a wrong drug error if drug X prescribed but drug Y given instead).

Unauthorised drug

This was considered to be the same as unordered drug error

Excluded. Same as unordered drug error.

Wrong drug Administration of the wrong drug was considered to an unordered drug error.

Included. A dose of a drug administered that is not the drug prescribed (does not include generic substitution or therapeutic substitutions in accordance with trust policy).

Wrong dosage form

Wrong dosage form errors involve the administration of a drug in a dosage form different from the one that was ordered

Included. The administration of the correct dose of the drug by the correct route but in a formulation that was not prescribed (includes administration of modified release when non-modified prescribed, and vice versa). Does not include administration of enteric coated drug instead of plain tablets if the patient states enteric coated is normally taken, or any appropriate purposeful alteration, such as substituting tablets with a soluble equivalent to help administration.

Wrong time A wrong time error occurs when the patient does not receive his or her medication within a predefined interval.

Excluded. Timing of drug administration in relation to the prescribed time was measured and reported but not included as an MAE.

Wrong route Wrong route errors occur when the correct form of drug is administered, but in the correct site on the patient’s body.

Included. The administration of the correct drug by a route or site that was not that prescribed.

Drug deteriorated A deteriorated drug error is reported when the physical or chemical integrity of a medication dosage form has been compromised, as with expired drugs or intravenous medications requiring refrigeration that are left out of the fridge.

Included. Administration of a drug that has exceeded its expiry date or a drug with its physical or chemical integrity compromised.

Wrong rate of administration

Wrong rate of administration errors can occur with infusions of intravenous fluids or liquid enteral products.

Excluded. The current study was focused on the administration of non-intravenous drugs. during administration of a drug. Examples include wrong inhaler technique and not wiping an injection site with alcohol.

Excluded. Wrong administration technique errors such as wrong inhaler technique were considered a wrong dose, and not wiping an injection site with alcohol was considered a violation of procedure rather than an error.

Wrong dose preparation

Wrong dose preparation error occurs when a product is incorrectly manipulated before administration. Examples include not shaking an oral suspension.

Excluded. If wrong dose preparation such as failure to shake a bottle of suspension resulted in a visible concentration gradient this is was considered a wrong dose error.

Extra dose An extra dose error occurs when the patient receives additional dosage units to those that were authorised, such as a dose administered after the order was cancelled.

Included. The administration of an additional dose of a prescribed medication (includes administration of a drug more times in the day than prescribed and administration of a dose of drug after it has been crossed off the chart).

Other error When the investigator believes that a medication error has occurred but does not fall into a predefined subcategory

Included.

2.4.3 Identifying the core tasks and defence barriers associated with the medication administration process

Pilot observations were conducted on the study ward to identify the core tasks and defence barriers associated with medication administration on non-IV drug rounds. Potential measures relating to the system effects were initially identified by noting common interactions between nursing staff and the medication systems used on the ward. The medication administration related measures specified in the Productive Ward toolkit were also considered for inclusion in the study: the number of MAEs and associated themes identified from medication incident reports, time taken to complete drug rounds, and number of interruptions per drug round.

To ensure the study measures were relevant and useful to staff at the study site, a group comprising four nurses of varying seniority from the study ward, the lead nurse for Medicine, the lead nurse for process improvement projects, and MM, reviewed the measures suggested in the Productive Ward toolkit and identified other potential quality measures for inclusion in the study. The quality and safety measures were based on those previously measured in other quantitative MAE studies, feedback from nursing staff on potential problematic medication administration-related areas, practicalities of data collection, and priorities for assessment locally. Additionally, two other measures were identified during the pilot observations and subsequently included in the study following discussion with the project group: (1) nurses often accessed the patient’s bedside medication locker to retrieve medications but doses were not always available. It was therefore decided to also document whether or not each dose was retrieved from the bedside medication locker. (2) There was variation in the prescribed times for doses in the morning i.e. 6am and 8am but both were administered at the same time by nursing staff, and therefore the prescribed time of each dose was also documented.

Evaluation of medication incident reports was excluded from the study (but continued to be reviewed according to local hospital policy) as the current study was focused on quantitative investigation of medication safety; this was discussed and agreed by the group. Both PhD

supervisors of MM provided further guidance on the measures chosen, and a final set of 10 was agreed (table 2.2).

Table 2.2 List of outcome measures included in observational study on the quality and safety of medication administration

Purpose Outcome measure

Primary outcome measure (i) Overall medication administration error rate Measures of the core tasks

and defence barriers for evaluating the overall quality and safety of the medication administration process

(ii) Timeliness of drug round relative to scheduled drug round time

(iii) Percentage of doses given after the patient’s identity was confirmed (as a match to the drug chart) prior to medication administration

(iv) Percentage of doses given and/or omitted for therapeutic reasons

(v) Percentage of doses that were given correctly (vi) Percentage of doses taken by the patient that were

observed by the nurse

(vii) Percentage of doses that were documented as administered or reason for omission recorded in the drug chart

Additional measures (viii) Availability of medication in the patient’s bedside medication locker or bedside area

(ix) Number of interruptions during drug rounds (x) Duration of drug rounds