Imperial College London

Missed medication is a major cause of harm in hospitals, study suggests


A pile of different pills

New Imperial research highlights the most common types of fatal drug administration errors in hospitals.

Around a third of the most serious drug administration mistakes in hospitals are linked with patients not receiving the medication that they need, according to new research published in the journal Research in Social and Administrative Pharmacy.

Among the other leading causes were people being given the wrong drug or the wrong dose, with cardiovascular drugs most commonly involved.

“It’s not possible to conclude why this is happening from the data,” says study author Professor Bryony Dean Franklin from the NIHR Imperial Patient Safety Translational Research Centre (PSTRC).

“But the fact that missed medications were identified in the largest number of these cases is partly because omissions are the most common kind of medication administration error, so there’s more opportunity for causing harm.”

A decade of data

Medicines save lives. But they’re not without risks. In fact, medication errors have been found as one of the leading causes of injury and avoidable harm in healthcare across the world. And the costs don’t end at people’s health: these mistakes are estimated to rack up a bill of $42 billion across the globe each year. In England alone, it has been estimated that some 237 million medication errors happen annually.

That’s why scientists from the NIHR PSTRC, in collaboration with the University of Eastern Finland, King’s College London and University College London, set out to better understand the underlying reasons behind such incidents.

“This was an exploratory study to find out the characteristics of these errors,” says Professor Anne Marie Rafferty, study author from King’s College London. “What types are occurring, where are they happening, and what sorts of patients and drugs are involved?”

The team led by University of Eastern Finland’s Dr Marja Härkänen pooled data on patient safety incidents from England and Wales spanning a 10-year period, from the start of 2007 to the end of 2016. They included NHS hospital trusts, rather than primary care practices such as GP surgeries, and looked for trends in the most serious medication administration errors that resulted in death.

Highlighting high-risk medicines

They found that errors were most commonly reported in people older than 75, which likely reflects the fact that this age group makes up a large proportion of patients in hospitals. The most common category of error was omission, where patients aren’t given a dose of a drug that they need, which accounted for around 31% of the incidents.

“This was an interesting finding, as people often believe that omissions are one of the less serious types of error,” says Franklin.

“We can only speculate why this could be happening,” added Rafferty, “but it’s likely to do with the complexity of the patient, the drug and the person administering the drug needing to be in the same place at the same time. This can be difficult when patients are on a complex medication schedule or need to leave the ward for a test or procedure.”

The team also discovered that the drugs most commonly involved were cardiovascular medicines, in particular injected anti-clotting drugs such as heparin. While cardiovascular drugs are commonly used, Franklin says, the findings suggest that these anti-clotting treatments could be particularly high-risk if errors occur.

Correlation versus cause

Learning about the reasons behind harmful events in healthcare is an important step towards improving patient safety. And while this research is helping to build a bigger picture of medication administration errors, Franklin stresses that people shouldn’t be concerned by the findings: “There were only 229 reported deaths out of almost 517,500 reported errors, so this is a small figure.

“And these error reports don’t necessarily mean that the error caused the death; these situations are often multi-factorial.”

Still, Franklin urges individuals to speak to a doctor or nurse if they think that a dose may have been missed in their schedule or if they have any other concerns.

Looking ahead, PSTRC researchers will continue to dig further into this topic, aiming to generate more robust evidence on why errors can sometimes happen and, in the process, aim to make hospitals a safer place for patients.


Justine Alford

Justine Alford
Institute of Global Health Innovation

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