• The technology described in this briefing is the FreeStyle Libre flash glucose monitoring system, which measures interstitial fluid glucose levels in people with diabetes.

  • The innovative aspect is that FreeStyle Libre measures glucose levels from a sensor applied to the skin as an alternative to routine finger-prick blood glucose testing, and can produce a near-continuous record of measurements which can be accessed on demand. It can also indicate glucose level trends over time.

  • The intended place in therapy is as an alternative to routine blood glucose monitoring in people with type 1 and 2 diabetes who use insulin injections. Finger-prick blood glucose measurements are sometimes still needed, such as when a person is ill or to meet the requirements of the Driver and Vehicle Licensing Agency in assessing fitness to drive.

  • The main points from the evidence summarised in this briefing are from 5 studies (6 papers) involving 700 people. These include 2 randomised controlled trials, 1 including people with type 1 diabetes (n=241; the IMPACT study) and the other including people with type 2 diabetes (n=224; the REPLACE study). Three of the studies reported device accuracy compared with self-monitored blood glucose, with results ranging from 84% to 88% accuracy and from 99% to 100% clinical acceptability, using an error grid. One study reported device accuracy and acceptability of 97% to 99% compared with venous blood sampling. The evidence suggests that using FreeStyle Libre for up to 12 months reduces time spent in hypoglycaemia compared with self-monitoring of blood glucose using finger-prick tests, and reduces the average number of finger-prick blood glucose tests needed.

  • A key uncertainty around the evidence is that the randomised controlled trial of people with type 1 diabetes included only adults whose diabetes was well controlled.

  • The current commercial list price of FreeStyle Libre is £57.95 for the reader, plus £57.95 for a disposable sensor (including VAT) that must be replaced every 2 weeks.

  • The resource impact is uncertain, and depends upon the extent to which improved glucose control through the adoption of FreeStyle Libre translates into fewer complications, reduced emergency admissions and less use of glucose test strips.