The call goes out.

“I need someone to check medication with me.”

Nurses are always looking for someone to check medication.

But there has been little evidence that the practice of double check reduces drug errors.

Many nurses believe that it is an effective way of minimising errors.

On first look, it does seem that this should reduce medication errors to zero.

Two people checking – what could go wrong?

It turns out that it does and the factors are very human.

Each checker can assume that the other is checking properly – and not do their own check as thoroughly and carefully as they should.

A systemic literature review concluded that there was insufficient evidence to support or disprove the use of double check.

A recent study by Douglass et al. conducted a randomized controlled trial looking at the effect  double checking had on the rate of medication error.

It found that a double check increases error detection in some situations.

But not in others.

Double check was better at picking up vial errors.

And was more effective than a single check in weight-based dosing errors.

In three cases, the presence of a second nurse actually dissuaded or rushed the first nurse into making an error.

In a rushed environment, a cognitive shorthand process can occur.

The study authors said

“This is a phenomenon in human factors science known as satisficing, in which one will not continue to look for and process additional information once the needed information has been detected.”

In a rushed environment where time is limited, even with two people, errors can occur.

The authors also point out that errors can occur due to poor packaging or process design.

More research is needed on double checking of medication.

The process of double checking is labour intensive and has limitations that may not be worth the cost.

Douglass et al. say that double checking of medication “may best be reserved for only the highest-risk medications.”

Other interventions that could be considered is barcode-assisted medication, error awareness training and a systems review.

To learn more about double check medication errors,

Douglass, Amy M., et al. “A randomized controlled trial on the effect of a double check on the detection of medication errors.” Annals of emergency medicine 71.1 (2018): 74-82.