Prescribing medicines has the potential to alleviate symptoms for patients, as well as to treat and prevent disease or illness. However, it also has the potential to do great harm (as evidenced in Box 1). Harm from medicines may be due to the drug itself or the way they are used by patients or professionals. The interfaces of care are common situations for error and harm to occur, such as the admission and discharge of a patient from hospital.
The medication error iceberg
Medication errors are frequent, however the detection and reporting of them is low. They range from potential errors through unnoticed errors, errors that don’t cause harm (near misses) to errors that cause harm.
One of the challenges is that the same error can cause completely different outcomes according to the setting and context, eg, prescribing a contraindicated drug or the right drug to the wrong patient may not cause any harm, or it could result in severe harm or a patient’s death (see case below).
Prescribing is a good example of the “Swiss cheese” model proposed by James Reason11, representing a combination of individual active errors and latent system errors resulting in error-producing conditions (the holes). As healthcare professionals we are more likely to make errors if certain error-producing conditions exist.
The slices of Swiss cheese represent steps in the process and possible layers of defence. The more layers of defence, the less likelihood that all the holes will line up and harm will occur. These layers of defence will probably be a mixture of individual, system and technological processes. Fortunately, most medication errors don’t cause significant harm, either because the potential for harm is small or one of the defensive barriers (layers of Swiss cheese), such as doublechecking by the pharmacist prevents the error from harming the patient.
There are many facets as to how we manage medicines, resulting from interplay between healthcare professionals, patients and their carers, the medicine itself and the systems we use. Recently the term “Medicines Optimisation” has emerged as a way of trying to focus all these influences and processes on producing the most beneficial outcome for the patient where medicines are involved.
This is particularly the case as polypharmacy becomes increasingly prevalent in an ageing population with multimorbidity and more indications for medicine usage. Polypharmacy can be appropriate or problematic as discussed in a recent review by the King’s Fund.12