Image copyright Science Photo Library Image caption The British Medical Association said referral management centres were "crude" and putting patients at risk

NHS patients face "dangerous" treatment delays due to a 10-fold increase in "crude, expensive" referral management centres, doctors have warned.

The centres, sometimes run by private firms, vet GP referrals and decide if patients should receive hospital care.

The British Medical Association (BMA) called them "inefficient" and a "block between the GP and patient treatment".

NHS Clinical Commissioners said "in many cases" the centres "provide a useful and effective role".

All but 12 of the 209 Clinical Commissioning Groups (CCGs) in England responded to a BBC Freedom of Information (FoI) request. Sixty-one of them said they used some form of referral management centre.

These centres were introduced in about 2003 and were designed to reduce NHS spending by limiting unnecessary referrals to hospital. However, one GP claimed cancer diagnoses were being delayed because of the extra bureaucracy.

Since 2005 there has been a 10-fold increase in the use of referral centres.

A BBC investigation revealed there had been a rise in referrals being rejected for administrative, rather than clinical reasons, with delays due to administration queries rising from 28% in 2013-14 to 41% last year.

Image caption Dr Chaand Nagpaul from the BMA said "performance seems to be related to blocking referrals rather than patient care"

Dr Chaand Nagpaul, from the BMA, said: "It's a blunt instrument which is not sensitive to the needs of the patient and is delaying patient care.

"It has become totally mechanistic. It's either administrative or not necessary for the patient. It's completely unacceptable. Performance seems to be related to blocking referrals rather than patient care."

MPs in North Durham have complained about a centre which is paid £10 for every referral letter it processes.

Some doctors in England are being offered thousands of pounds by CCGs to cut the number of patients being referred to hospital.

About £19m was spent on the centres in 2015-16 and about two-thirds of the CCGs which responded to the BBC FoI request were not able to say whether the system was saving the NHS any money.

Referral management centres

Each centre operates differently, with staff of different levels of clinical knowledge, some redirect and reject referrals, others provide a booking management service for patients.

Referral centres are not used in the same way in Wales, Scotland and Northern Ireland.

About two million referrals were processed by these centres last year and the number being returned to GPs has gone up by about 30% for the past two years.

About 84,000 referrals were returned in 2015/16 - 4% of all those processed

Data gathered by the BBC has shown the most common reasons for referrals to be sent back were due to missing information or a requirement for the GP to carry out further tests.

One doctor in north-east England, who wished to stay anonymous, told the BBC: "The system is dangerous.

"In one case referral of a patient to a dermatologist was rejected by the referral management system. It turned out to be a cancer…That was a disaster."

Image caption Tracy Jefferies borrowed almost £3,000 to pay for private surgery to treat her varicose veins after she was told it was not offered by the NHS

In May, Tracy Jefferies had her referral to surgically strip her varicose veins rejected by Devon Referral Support Services.

The reason given was that she did not meet new criteria for treatment because Northern, Eastern and Western (NEW) Devon CCG changed its policy on treatment of the condition.

She said: "The swelling never went down and at night I could barely move. There wasn't a time in the day I wasn't in pain for it.

"I was told on the phone I did not meet the criteria to get treatment on the NHS. I was gobsmacked.

"I had to borrow money from my dad to pay for the treatment privately. So far I've spent over £2,000."

NEW Devon CCG said: "Unless an exceptional case is presented, the CCG will not fund the treatment of varicose veins."

Image caption Dr Graham Jackson from NHS Clinical Commissioners said referral management centres can "provide a useful and effective role"

The organisation which represents CCGs, NHS Clinical Commissioners, said: "CCGs will balance the cost of commissioning referral management centres with the benefit they provide to GPs and patients in terms of peer review, education, caseload management and choice.

"Ensuring patients get the best possible care against a backdrop of increasingly squeezed finances is one of the biggest issues CCGs face, but we know that clinical commissioners are working hard to improve local services by making responsible, clinically-led decisions in partnership with GPs, patients and providers."

Watch BBC Inside Out's investigation into rationing of the NHS at 19:30 BST on BBC One, Monday 16 January.