Many patients with severe rheumatoid arthritis are being denied effective drugs, say campaigners.
Rheumatoid arthritis can cause severe pain
The National Institute for Health and Clinical Excellence (Nice) has said anti-TNFa drugs should be provided by the NHS across England and Wales.
But a study has found lack of funds in many NHS trusts is preventing many patients from benefiting from them.
It was commissioned by the British Society for Rheumatology and the Arthritis and Musculoskeletal Alliance.
Most people with rheumatoid arthritis respond to standard immunosuppressant drugs, but around 15% have symptoms so severe that these drugs are of little help.
It is these patients who have most to gain from being given access to anti-TNFa drugs.
Doctors estimate almost 1,700 rheumatoid arthritis patients who could benefit from the drugs are being denied treatment.
The results suggest little has changed since a similar survey was carried out in 2003.
Professor David Isenberg, BSR president, said the findings were "very disappointing".
He said: "It is immensely frustrating for doctors to have patients who clearly qualify for anti-TNFa intervention but are unable to get it.
"These drugs offer hope and relief to people who have severe rheumatoid arthritis, and are likely to be affected by high levels of pain and disability, making their day to day living very difficult."
Di Vara works for the NHS in the Health Secretary Patricia Hewitt's constituency of Leicester West.
He was diagnosed with rheumatoid arthritis almost eight years ago, and has been told he should receive the treatment.
But his consultant has told him that there is a three year waiting list in Leicestershire.
He said: "I love my job, and feel I still have a lot to give, but if I don't receive any therapy fairly soon I might have to pack my job up."
The survey of 148 rheumatology units across the UK found that 31% of doctors were unable to provide the treatment to all patients who qualified for it. More than 50% blamed a lack of funding.
Many doctors also said they were unable to provide the drugs to people with other arthritis-related conditions, such as ankylosing spondylitis (AS) and psoriatic arthritis (PSA).
Professor Isenberg said: "It is wrong that some people are being left with unnecessary pain and disability.
"The Department of Health should remind health trusts they need to take urgent and immediate action to ensure people get the treatment they are entitled to."
Neil Betteridge, of the charity Arthritis Care, said: "It is extremely worrying that thousands of people are being forced to live in severe pain as a direct result of being unable to access the treatment they so desperately need.
"Our helplines team receives hundreds of calls every year from people desperate for information about how they can access anti-TNF treatment. Many feel they have been abandoned by the system."
A Department of Health spokeswoman said specialist teams based in every strategic health authority were being introduced to provide advice, care and treatment for people with chronic diseases like arthritis.
Two new classes of drugs had also been made available to NHS patients with arthritis following reviews by NICE.
Health minister Jane Kennedy said she believed NHS trusts had a statutory duty to provide the drugs for people who would potentially benefit, and lack of funding was not an acceptable excuse.
"Clearly patients are being let down if they are not being provided with these drugs."