Reducing errors within Oncology

Where are these errors occurring?

Until zero errors occur, the level of medication errors in oncology is still too high and therefore there is clearly room for improvement. Data from published literature of European studies highlights the specific level of errors in each step of the med journey:

Prescribing Phase – a study conducted in Ireland reported 29% of handwritten chemotherapy prescriptions contained at least 1 prescribing error or omission². Using the findings from a separate study that reported 1.8% of these types of prescribing errors would not get intercepted³, this equates to approximately 6% of the errors within the Ireland study potentially reaching the patient.

Preparation Phase – a large multicentre study in Europe involving 759,060 chemotherapy preparations showed the mean out-of-tolerance error rate during compounding to be 10.44%⁴

Administration phase - a large observational study carried out in both an inpatient and outpatient oncology setting reported the risk of administration errors of intravenous (IV) chemotherapy to be 27.3%⁵

Medication errors can occur at any stage. As they could result in both serious toxicity to the patient, or underdosing and therefore suboptimal patient outcomes, error prevention at all stages is crucial.

A closer look at errors in the prescription phase

This issue was addressed by Ranchon in the European Journal of Cancer⁶. This study aimed to identify the predictors of prescription errors involving anticancer chemotherapy agents. The study was conducted in a large university hospital in France and analysed 17,150 chemotherapy prescriptions. Prescription errors were defined as failures in the treatment process, which led to, or had the potential to lead to patient harm.

How to reduce prescription errors

Two independent studies showed that Computerized Physician Order Entry (CPOE) systems cut medication error rates in a hospital by approximately two-thirds^7,8. CPOE systems achieve this by providing standardized protocols, aligning the prescription with the patient’s latest clinical results, providing dose calculations and cumulative dose information, and automatically alerting the prescriber if a dose is outside the recommended limits. They also ensure clear and legible prescriptions, decreasing the risk of errors that can be brought about with look-alike drug names.

A closer look at errors in the compounding phase

A 2018 Canadian observational study investigated IV chemotherapy compounding latent errors¹⁰. A latent error is an underlying potential human failure, for example the storage of look-alike drugs besides each other. Within the study, 11 latent errors were identified across four cancer centres in Canada, all of which could lead to the death, or permanent loss of function among patients with cancer. These 11 latent errors are detailed below, grouped by process category:

Transcription of the prescription

1. Compared with electronic transcription, human transcription is error prone. If an error in transcription were to occur, it has the potential to propagate downstream through the system, meaning that a patient could receive a preparation that contains any type of error, including wrong drug or wrong dose.

Assembly of materials

2. Assembly of more than one preparation per tray creates the potential for the wrong drugs, syringes, final containers, preparation instructions, and/or labels to be loaded into the Biological Safety Cabinet (BSC) which would lead to compounding errors.

Reconstitution

3. If an error in reconstitution occurs, no way of detecting it downstream may exist and could result in a significant dose error. Drug-specific reconstitution protocols and independent reconstitution checks, therefore, are critical.
4. One site had a single document outside and to the right of the BSC that listed all the drugs’ reconstitution instructions. Therefore, a technician would need to lean outward and scan the whole document to find a specific drug’s instructions and then interpret them correctly.
5. Another site had no live inspection of reconstitution: The pharmacist verified reconstitution only after the completed preparation had left the clean room.

Preparation of the drug

6. The two sites that assembled patients’ preparations in the same tray also sometimes had one or more preparations in the BSC at once. A mix-up of drug, dose, and/or label, therefore, was possible.
7. Three of the four sites chose to avoid removing partially used vials of chemotherapy drugs from the BSC until the end of the day. The risk of having additional high-risk vials in the BSC along with the target vials is the same as having more than one preparation at a time.
8. To reduce environmental waste, one site reused a syringe as many times as necessary to achieve a target volume. Without being able to see all the syringes at once, reliable confirmation of the total volume is difficult.

Verification and labelling of the compound preparation

9. Two of the four sites used a variant of the denounced syringe pullback method. At both sites, the preparer’ would withdraw the drug into the syringe and inject it into the final container without direct observation by a second individual. Although a weight-based check could catch potential preparation errors, some errors could easily be missed. For example, an error in re-constitution could be made but the correct volume of drug withdrawn, or two errors could cancel each other out to create the correct weight
10. At two sites, the ‘preparer’ spoke aloud the name and volume of drug just withdrawn, for example, “five of cyclophosphamide.” Telling the checker what to expect can create confirmation bias.
11. At two of the four sites, administration labels were affixed after the preparation left the BSC, which created the potential for the labels to become lost and/or mixed up and, ultimately, applied to the wrong final container.

How to reduce compounding errors

Automated IV medication workflows using gravimetric technology can be used for the preparation of cytotoxic drugs instead of the traditional manual workflows using volumetric preparation. Automated workflows provide step-by-step instruction to guide the user through the compounding process, and combined with barcode scanners, gravimetric scales and cameras, help ensure the correct preparation of a drug.

Two studies reported evidence showing the benefit of automated IV medication workflows (BD Cato™) with regards to reducing compounding errors:

Reece 2016 described the implementation and evaluation of a gravimetric IV workflow software system in an oncology ambulatory care pharmacy¹¹. Over the study period, 51,037 chemotherapy doses were prepared without a workflow software system, with a total of 49 errors (0.096%) reported. 15,843 doses were prepared utilizing the new technology, with a total of 1,126 errors (7%) detected by the workflow software during dose preparation; barcode scanning detected 292 (26%) of the total errors, the gravimetric weighing step detected 797 (71%) deviation errors, and 37 (3%) errors were detected at the vial reconstitution step. The implementation of this workflow software system resulted in an over 74-fold increase in the detection of medication errors and allowed the errors to be corrected before completion of the dose, unlike without the software system.

Terkola 2017 aimed to detect medication errors with possible critical therapeutic impact in 10 centres across five European countries following the introduction of a gravimetric IV workflow software system⁵. The mean out-oftolerance error rate across the 10 centres, which prepared 759,060 chemotherapy doses, was 10.44%. The proportion of chemotherapy preparations with deviations >10% of the target dose ranged from 0.49% to 5.04%, with a mean of 2.25%. It is highly likely these errors would have gone undetected using traditional volumetric preparation. Additionally, all the errors detected with the gravimetric system during the preparation process did not need to be corrected postproduction, resulting in a reduced technician compounding time and reduced pharmacist preparation time of 34% and 37% respectively.

A closer look at errors in administration phase of oncology

Administration of chemotherapy is an important aspect of cancer nursing. Treatment regimens typically involve several chemotherapeutic and supportive agents, many of which require individualized dosing (e.g. body surface area, renal function), are administered by a variety of routes (e.g. orally, IV), and at different rates (e.g. bolus, continuous infusion). Delivery of a regimen on one day of a patient’s cycle can take several hours and involve multiple nurses. This complex and dynamic nature of chemotherapy administration makes the process highly vulnerable to errors.

In a prospective, systems-focused clinical risk assessment at an oncology unit in a large city hospital in the United Kingdom, several specific chemotherapy failure modes relating to chemotherapy administration were identified, the majority of which had not previously been recognized¹². These are shown in the table below.

Identified Failure Modes and Related Hazard Scores

Beyond the reduction of errors, within BD we are working across all aspects of oncology to continuously optimise patient outcomes by providing connected workflows and automating manual processes, while continuing to protect healthcare workers. We work with our partners, clinicians and healthcare professional to provide a seamless end-to-end solution for all oncology professionals.

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