However, the findings show that thousands of patients suffering from cancer, motor neurone disease and an eye condition which is the most common cause of blindness, are not being given the best medication.
The research examined 10 common treatments which have been backed by Nice, meaning they should be given to all patients who require them.
It found that in three of the groups, there was a gulf between the number of patients who should have been given the drugs and the numbers who were actually prescribed them.
The worst findings were for kidney cancer, which affects more than 8,000 patients a year, and for a form of motor neurone disease which affects almost 3,000 people.
One in three patients who could have benefited from sunitinib (which has the brand name Sutent) and pazopanib (brand name Votrient), life-extending drugs for kidney cancer, or from riluzole (brand name Rilutek), the only treatment for motor neurone disease, did not receive them.
More than 12,000 patients were denied injections for wet age-related macular degeneration (AMD), the most common cause of vision loss and blindness.
Nice makes rulings on whether drugs are effective and good value, but has been criticised for refusing to support drugs in the face of evidence that they can extend lives by months or even years, and for delaying decisions.
But the findings suggest that even when Nice says NHS bodies must fund the drugs, thousands of patients are still denied medication.
Charities said too many terminally-ill patients ended up fighting bureaucratic procedures in an attempt to secure NHS funding for treatment.
In other cases, they were never told about drugs such as Sutent, which can double life expectancy with kidney cancer to 28 months, and was approved by Nice more than four years ago.
Andrew Wilson, the chief executive of the Rarer Cancers Foundation, said patients were suffering from “an endemic postcode lottery in access to Nice-approved medicines”.
“It is extremely worrying that the NHS does not seem to be making available cancer treatments to all patients who could benefit, even when the drug is approved by Nice,” he said.
Nick Turkentine, the chief operating officer of the James Whale Fund for Kidney Cancer, said the failure to follow national guidance was “a disaster” for patients with aggressive cancers. He said: “Sutent was one of the first drugs to be approved for kidney cancer — it is really disastrous that patients are still having to battle for a drug which we know can give several extra years of life.”
Duleep Allirajah, the head of policy at Macmillan Cancer Support, said: “Patients do not choose which cancer they get. Every patient deserves equal access to treatment no matter who they are, where they are from, or which cancer they have.”
A spokesman for Nice said the organisation hoped the report would help ensure that guidance was followed more widely, and that local NHS groups needed to be able to justify variations from it.
A spokesman for the Department of Health said: “Patients have a right to drugs and treatments that have been approved by Nice and we expect the NHS to provide them if they are needed.
“That is why the chief executive of the NHS has written to the local NHS requiring them to publish which NHS organisations are funding and using drugs and treatments approved by Nice, and which are not.”
Drugs whose use was lower than expected:
• Riluzole (Rilutek) - the only treatment for motor neurone disease - 35 per cent of patients who would have been expected to receive the drugs did not.
• Sunitnib (Sutent) and pazopanib (Votrient) for kidney cancer - 32 per cent of patients who would have been expected to receive the drugs did not.
• Ranibizumab (Lucentis) - the most effective treatment for wet age-related macular degeneration, which can cause blindness - 5 per cent of patients who would have been expected to receive the drugs did not.