to increase awareness of medication errors through open communication, increased reporting and promotion of medication error prevention strategies. ⁴ Primary objectives of this council include medication error reporting, understanding and prevention. The NCC MERP allows the patient or healthcare professional to report an error to USP or MedWatch. USP also has another reporting system, Medmarx, which is a subscription-based reporting system that allows hospitals and other healthcare facilities to collect, analyze and share types of medication errors and solutions for prevention. These organizations have created reporting programs to prevent harm to patients, increase awareness about medication errors among the medical community and to encourage a systems-based approach to enhancing patient safety.

an adverse drug event (ADE), more specifically, is an adverse event involving medication use.

Two types of ADEs include adverse drug reactions (ADR) and medication errors. An ADR is an adverse effect caused by the use of a medication in the recommended manner and is typically unpredictable, unpreventible and occurs at the patient level or at the end of the medication use process. A medication side effect would be an example of an ADR.

A medication error is a preventable ADE and can occur throughout the medication use process. A side effect from a drug that was incorrectly prescribed would be classified as a medication error.

According to USP, the medication use process involves five steps: prescribing, documenting, dispensing, administering and monitoring. The NCC MERP more specifically defines a system to include prescribing, order communication, product labeling, packaging and nomenclature, compounding, dispensing, distribution, administration, education, monitoring and use. Errors can occur in any of the steps.

An error also can be considered active or latent. An active error is one that has immediate effects and is readily apparent. In comparison, latent errors have delayed results, are less visible and are errors in the design, organization, training or maintenance of a system. Medication errors are classified as latent errors.

Additionally, an error may be viewed as the result of an act of commission or omission—doing something wrong or failing to do the right thing, respectively.

And, finally, errors may be classified by the degree of harm they cause. In 1996 the NCC MERP adopted the Med-

TABLE 3

ISMP’s 10 subprocesses of the medication use system

Subprocess Why the error occurred in the subprocess

1. Patient information Not obtaining the patient’s pertinent demographic information to make key medical decisions (e.g., age, weight, allergies, pregnancy, breast-feeding)

2. Drug information

Not having updated or accurate drug information; not having a variety of sources to obtain updated information

3. Communication of drug information

Written or verbal miscommunication at any level between the physician, pharmacist or patient

4. Drug labeling, packaging and nomenclature

Look-alike and sound-alike medications

5. Drug storage, stock and standardization

Lack of standardization of drug administration times or drug storage

6. Drug device acquisition, use and monitoring

Device related error and lack of double-checks

7. Environmental factors

Poor lighting, noise, interruptions

8. Competency and staff education

Lack of staff education or training of new medications, policies or procedures

9. Patient education

Lack of or poor education of the patient from either the physician or pharmacist on their medications (e.g., indication, dose, side effects, interactions)

10. Quality processes and risk management

Focusing on individual blame and not the system

DEFINING MEDICATION ERRORS

The working definition of a medication error, as stated previously, is “any preventable event that may cause or lead to inappropriate medication use or patient harm … such events may be related to professional practice, healthcare products, procedures or systems…” ^{1, 4} (Table 1^{12, 13}). In general, an adverse event is any injury caused by medical care and

ication Error Index that classi-fies an error according to the severity of the outcome and harm to the patient (Table 2). ¹⁴ The goal of this nine-category index is to create standardization among healthcare providers and institutions for tracking medication errors.

TABLE 4

NCC MERP Taxonomy of Medication Errors

1. Patient information

2. Medication error event 3. Patient outcome

4. Product information 5. Personnel involved

6. Type of medication error

7. Causes

8. Contributing factors

THE MEDICATION USE PROCESS

Both the NCC MERP and ISMP have identified the types and causes of medication errors. In addition to the medication use process model of error, ISMP further identifies 10 subprocesses within the system where there can be quality failure and the potential cause (Table 3). ³ Errors identified during each of these processes may be the responsibility of the prescriber, pharmacist, patient or manufacturer.

In 1998, the NCC MERP created the Taxonomy of Medications Errors. This document provides a standard

for recording and tracking the type of medication error and its potential cause by analyzing the system being used (Table 4). ¹⁵ Of the eight areas of taxonomy, there are five potential causes of error identified by the NCC MERP including communication, name confusion, labeling, human factors and product packaging or design. The common theme of both organizations is analyzing errors using a systems approach as opposed to focusing blame on an individual.

Types of error

Prescribing errors occur at the practitioner level. The prescribing phase involves patient evaluation, assessing the need for medication, choosing the correct medication, individualizing the regimen, determining interactions, assessing allergies and prescribing the selected drug. Drug administration is another phase of the system where error can

occur, and in the community setting, this type of error is at the patient level. Also known as compliance errors, they occur due to inappropriate patient behavior or adherence issues. The dispensing phase encompasses choosing the correct product, drug preparation or compounding, contacting the presciber for dis-crepancies and dispensing a drug in a timely manner. Part of the dispensing phase includes patient counseling and this involves informing the patient about their medication and encouraging adherence. The manufacturer also plays a role in the accuracy of the dispensing phase by developing appropriate labeling and packaging of a drug product. In a U.K. study by Ashcroft et al., 35 community pharmacies recorded detailed reports of all incidents that occurred during the dispensing process over a four-week period. ⁷ Pharmacists recorded 330 incidents related to 310 pre-