PILLS - Prescribing errors

Never events

(see never event data in Prescribing for special groups)
The Department of Health publish a list of “never events” which are defined as serious, largely preventable patient safety incidents that should not occur if the available preventative measures have been implemented by healthcare providers (Department of Health, 2011). Several of these relate to medicines:

- wrongly prepared high-risk injectable medication
- maladministration of potassium-containing solutions
- wrong route of administration of chemotherapy
- wrong route administration of oral/enteral treatment
- intravenous administration of epidural medication
- maladministration of insulin
- overdose of midazolam during conscious sedation
- opioid overdose of an opioid-naïve patient (i.e. a patient who has never previously received an opioid)
- inappropriate administration of daily oral methotrexate

What do you think of this list and is it useful?

Which patients are most at risk from error ?

As we have seen in prescribing red flag medicines as well as specific drug groups, certain types of patients may be more susceptible if errors occur. Those who are at the extremes of age i.e. neonates, infants and older people, are at a greater risk from prescribing errors due to altered pharmacokinetics and pharmacodynamics. Patients who have multiple co-morbidities and those who receive multiple medicines (polypharmacy) are also at greater risk (NPC, 2010). One of the most risky times is when patients undergo transitions in care e.g. on admission to, or discharge from, hospital; or admission to a care home (Royal Pharmaceutical Society, 2011). Patients may also be at risk if they do not understand the purpose of their medicines or have difficulty taking them. Looking at Adverse Drug Reactions and Drug Interactions you will see a pattern emerging which should increase your awareness when prescribing these drugs and for these patients. Prescribing for specialist groups expands on these ideas.

Why do prescribing errors happen?

As Seneca (1-65 CE) noted 2000 years ago, to err is human. The psychology of human error (Human Error Theory) has been studied in critical safety industries (e.g. nuclear, aeronautics) and is now widely applied in medicine to understand the causes of errors in order to develop solutions to minimise their prevalence and impact (Vincent, 2010). Key to Human Error Theory is a recognition that the systems that you as doctors work in, can contribute to error (Dean et al, 2002). For a prescribing act to be successful two conditions need to be fulfilled (i) an appropriate plan needs to be formulated, and (ii) the plan needs to be successfully executed (Aronson, 2009; McDowell et al, 2009). If the plan is wrong, then a mistake occurs. A failure to execute an appropriate plan is termed a slip or lapse. Mistakes will happen; there are very few if any practitioners who have not made an error at least once. Your task is to ensure this happens rarely. You need to learn from errors and ensure that if they were preventable that lesson is clearly learned.

Mistakes

Knowledge-based mistakes result from a lack of knowledge about a patient or drug. Examples include prescribing penicillin without knowing a patient had previously suffered an anaphylactic reaction to penicillin, or prescribing Augmentin® to a penicillin-allergic patient not knowing that it contains a penicillin (Aronson, 2009). Mistakes can also occur by applying bad rules or by not applying/misapplying good rules e.g. prescribing asthma therapy for a patient with chronic obstructive pulmonary disease (Vincent, 2010); prescribing medicines for symptoms that may be the result of an adverse drug reaction and continuing to prescribe repeat medicines after the condition has been cured.

Slips and lapses

Slips and lapses are errors in executing good plans (skill-based errors). Slips are errors of commission e.g. selecting bisocodyl instead of bisoprolol from a drop-down computer list, whereas lapses are errors of omission e.g. intending to write up a statin for a patient who has had a myocardial infarction but forgetting.

Violations

Violations are intended deviations from protocol or policies (McDowell et al, 2009) and include abbreviating drug names, not providing full information on the prescription and using abbreviations for dose units e.g. µ or mcg for micrograms. Violations are usually employed to save time.

Accident causation model

Reason (1990) developed the Accident Causation Model to explain the causes of error. In the model, mistakes, slips/lapses and violations are described as active failures. As mentioned previously, the system in which you prescribe can contribute to error and this is influenced by organisational decisions that are termed latent conditions.

Active failures

Think of how these active failures could occur in the place in which you practise. Discuss the ideas with colleagues and write them down.
As mentioned previously, the system in which you prescribe can contribute to error and this is influenced by organisational decisions that are termed latent conditions.

Latent alerts

Think of examples of latent failures that you have seen in the place in which you practise. Discuss the ideas with colleagues and write them down.

Activity
An example of a latent condition may be that there are poor systems for communicating medication histories between the GP and hospital. In addition to latent conditions, error producing conditions also contribute to active failures and these include being tired, stressed, hungry etc. Error producing conditions may also be related to the particular task at hand or related to the patient e.g. a patient has severe dementia and therefore, an accurate history is unobtainable. Ultimately, latent and error producing conditions can result in active failures i.e. a prescribing error. To mitigate against this, defences are built into healthcare systems to detect and prevent errors from reaching patients. These are discussed in the next section.