NHS England case study: Confusion between blood glucose and blood ketone test strips (26 January 2026)

Summary

This case study is one in a set of NHS England patient safety ‘how we acted on patient safety issues you recorded’ case studies which show the direct action taken in response to patient safety events recorded by organisations, staff and the public, and how their actions support the NHS to protect patients from harm.

Content

The National Patient Safety Team identified an incident where the incorrect treatment was given to a patient when the wrong point of care (POC) test strip was used. This led to a ketone result being interpreted as a blood glucose result. 

Mistaking a ketone value for a blood glucose value can obscure detection of dangerously high levels of ketones in the blood, ultimately leading to a harmful condition called diabetic ketoacidosis (DKA).

A review of incident data revealed other examples of wrong strip selection due to their visual similarity, local labelling, and storage issues. The review also showed that some staff didn’t realise that certain POC devices can be used with multiple different strips.

Despite the strips meeting design and packaging criteria to prevent such errors, it was clear the potential for errors exists.

A request was made to include insight from our review into educational material through the National Association of Medical Device Educators and Trainers (NAMDET) and POC leads. 

Resources for the management of hospital POC systems also now exist to support the implementation, management, and use of POC devices in clinical practice.