Tens of thousands of UK patients with type 1 diabetes are being denied the potential benefits of flash glucose monitoring devices because of a postcode lottery, an investigation by The BMJ has found.
Abbott's Freestyle Libre is currently the only device available in the UK.
But the investigation shows that a year after the device became available, around a quarter of clinical commissioning groups (CCGs) in England are not recommending it for patients even if they meet NHS England criteria.
There are roughly 400,000 people in the UK with type 1 diabetes, including the UK prime minister Theresa May, who uses Freestyle Libre and recently told parliament that it is available on the NHS.
But Partha Kar, NHS England's associate national clinical director for diabetes, estimates that only around 3-5% of patients with type 1 diabetes in England currently have access to the sensor on the NHS. If CCGs were following guidance correctly, he believes this figure should be closer to 20-25% - if not higher.
He said some CCGs were merely paying "lip service" to offering access to the devices, and that variation in how the criteria were being applied had led to an unacceptable postcode lottery.
Consultant diabetologist Emma Wilmot, who treats patients who can access the device and others who can't, says some patients are considering moving to a different GP practice a few miles down the road to meet the criteria, while others were making "huge sacrifices" to fund Libre themselves.
Data disclosed by CCGs to The BMJ in response to Freedom of Information requests show that some CCGs have made the devices available to hundreds of patients via GPs and have spent thousands on prescriptions, while some say that the devices are only prescribed by secondary care clinicians.
And some CCGs are imposing stricter access criteria than those recommended by NHS England leading GPs to ignore this advice because they believe the device will help their patients.
Meanwhile, official prescribing data collated by the diabetes campaigner Nick Cahm and shared with The BMJ suggests that only 2% of patients with type 1 diabetes in England are getting Libre on GP prescription, compared to 11% in Scotland, 16% in Wales, and 35% in Northern Ireland.
As of July 2018, GP prescribing data showed that only only two out of 195 CCGs in England had prescribed Freestyle Libre to more than 20% of patients with type 1 diabetes, only 15 CCGs had prescribed it to over 10% of type 1 patients, and 25 CCGs had issued no prescriptions at all.
Cahm told The BMJ: "Lots of the variation doesn't need to be there. Being a type 1 diabetic is the same whether you're in Birmingham, London, or Northern Ireland. It doesn't seem to be logical. Decisions should be made by a specialist advisory panel."
The BMJ has also learnt that some GPs in areas where CCGs have not recommended flash monitoring are prescribing Freestyle Libre against their CCG's advice.
Nick Cahm said that some CCGs were only thinking about their short term finances rather than long term gains that could occur if patients type 1 diabetes have better control of their condition, and suffer fewer complications in years to come.
Emma Wilmot believes that Freestyle Libre is one of the biggest "life changing" advancements in type 1 diabetes care for many years, and that "by preventing people having access to the Libre you are compromising their quality of life compared to what it could be."
Julie Wood, chief executive of NHS Clinical Commissioners, said: "Unfortunately the NHS does not have unlimited resources and ensuring patients get the best possible care against a backdrop of spiralling demands, competing priorities and increasing financial pressures is one of the biggest issues CCGs face."