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Best-selling author Terry Pratchett tells Panorama how he was forced to pay for his own Alzheimer's medicine after being denied it on the NHS.
The government has promised to speed up access to new drugs on the National Health Service (NHS) and end the apparent unfairness of postcode prescribing.
But as Panorama reports in The NHS Postcode Lottery: It Could Be You it is not delivering on that pledge and instead what medicines you receive in some cases still comes down to three vital words: location, location, location.
In 1999 Labour set up the National Institute for Health and Clinical Excellence (NICE) in part to end these sorts of inequalities.
NICE decides which medicines should be available to NHS patients in England, Wales and Northern Ireland; in Scotland it is up to the Scottish Medicines Consortium (SMC).
Both NICE and the SMC use a complicated calculation to work out whether a drug is worth paying for, weighing up its costs against the benefit it is likely to bring.
But some physicians say that their method of calculation is fundamentally flawed and that patients are missing out on drugs which could be of immense benefit as a result.
For a drug to be widely available through the NHS in England, Wales and Northern Ireland it has to have been given the green light by NICE.
If it is not, then even if the drug has been proven to be a safe and effective treatment for your illness, you cannot get it free through the NHS unless you are granted exceptional funding.
And therein is the catch.
Naomi Kiely has found it difficult to get the cancer drug Avastin
Doctors apply on behalf of individual patients for exceptional funding from local health boards or primary care trusts (PCTs).
But depending on where you live, the various criteria of your health board or PCT can have a profound effect on your likelihood of success.
In The NHS Postcode Lottery: It Could Be You, reporter Shelley Jofre meets patients and doctors falling foul of this system such as Naomi Kiely, a 30-year-old Manchester woman battling bowel cancer for the second time in four years.
Miss Keily applied for exceptional funding for Avastin, a drug which would treat her cancer, but with far fewer side effects.
She was turned down.
But as the NHS Postcode Lottery: It Could Be You reports, patients living in Cheshire have a much higher chance of getting non-NICE approved cancer drugs than those living in Manchester.
To provide a snapshot of what is happening on the ground the programme reports on a case of patient inequality in Essex where a doctor treating three people for exactly the same eye disease, treats each differently because they live in three different areas.
One of the three is getting Lucentis the drug tailored to treat their condition, the second receives a drug which was not designed to treat the eye condition; but which does the job at a much smaller price, while the third is left with no drug therapy at all.
Aricept is only available free in the late stages of Alzheimer's disease
The programme also spoke to best-selling author Terry Pratchett who has been forced to look elsewhere for Aricept, the Alzheimer's medicine denied to him by the NHS.
NICE ruled that Aricept should be limited through the NHS to people in the later stages of the disease and Pratchett is still in the early stages of PCA, an early-onset form of Alzheimer's which he was diagnosed with in 2007.
The author now pays for the drug himself which he says has been vital in allowing him to cope with the symptoms of his condition, and says that not making it available earlier to other sufferers who cannot afford to pay is "an insult" which needs to be rethought.
The NHS Postcode Lottery: It Could Be You also examines the situation north of the border, asking if Scotland is faring any better.
In Scotland it is the SMC which decides which drugs should be widely available through the NHS, although in practice the rulings made by NICE are usually adopted there too.
As we all know having the right postcode can put thousands on your house and get your kids into the best school, but in The NHS Postcode Lottery: It Could Be You, Panorama asks should it also determine whether you get medicine that could keep you alive?
Panorama: The Postcode Lottery: It Could Be You will be on BBC One at 8.30pm on Monday 18 August.