NHS bodies are paying millions of pounds to private firms that stop patients being referred to hospital by their GP, an investigation has found.
Controversial referral management centres are used by some clinical commissioning groups (CCGs) to scrutinise patient referrals to hospitals by family doctors.
Supporters say they can cut down on inappropriate referrals, saving the NHS money, but critics argue that adding an extra layer of scrutiny can risk delaying diagnosis for the patient. There is also a question mark over how effective such schemes are.
In a new investigation, the British Medical Journal (BMJ) sent freedom of information requests to all 211 CCGs in England. Of 184 that responded, 72 (39%) said they currently commissioned some form of referral management scheme to help manage outpatient demand at their local hospitals.
Almost a third (32%) of the schemes are provided by private companies, while a further 29% are provided in house and 11% by local NHS trusts.
Some 69% of CCGs with schemes gave details of operating costs. These CCGs combined have spent at least £57m on schemes since April 2013.
Most CCGs were unable to provide evidence showing the scheme saved money. Only 14% could show that the scheme had saved more cash than it had cost to operate, while 12% showed that their schemes had not saved money overall.
Meanwhile, 74% of CCGs (53 groups) failed to supply figures to show whether any money had been saved, the BMJ reported.
Some CCGs did not collect data on savings, some said that their referral scheme was designed not to save money but to improve the quality of referrals, and others refused to disclose details of savings on the grounds of commercial confidentiality.
Overall, there were 93 referral management schemes in operation across 72 CCGs, with some CCGs having more than one scheme.
Dr Richard Vautrey, deputy chairman of the British Medical Association's GPs committee, told the BMJ: "(CCGs) are leaping at these schemes without any clear evidence of benefit and that they're just hopeful that it might reduce their costs.
"It is a very, very short term approach to healthcare management. We need to see much more evaluation...and not just keep making the same mistakes year after year."
He added: "As public bodies, there should be an expectation on every CCG to account for what it's doing."
However, Dr Vautrey said some schemes were helpful because they gave GPs rapid access to advice from local specialists.
Graham Jackson, from NHS Clinical Commissioners, the membership organisation which represents CCGs, said referral management was just one way of managing demand for services.
He said: "In many cases they provide a useful and effective role which is more than a redirection service. CCGs will balance the cost of commissioning with the benefit they provide to GPs and patients in terms of peer review, education, caseload management and choice."
In October, Durham Labour MP Roberta Blackman-Woods criticised a local scheme to screen referrals for conditions including cardiology, gynaecology and gastroenterology.
North Durham Clinical Commissioning Group has awarded a contract to private firm About Health to manage referrals.
Chris Naylor, senior fellow in health policy at the King's Fund, said: "It is important not to judge referral management schemes on purely financial measures, as their main focus should be on improving the quality of referrals rather than on reducing costs.
"While there may be some potential to save some money, an effective scheme will highlight under-referral as well as over-referral, and so lead to people getting referred who otherwise may not have done.
"Compared to other ways of improving the quality of referrals, referral management centres come with significant overheads and can potentially introduce new clinical risks, so it is important that local schemes are evaluated to make sure the benefits, both financial and clinical, outweigh the costs.
"Our research suggests that the best approaches tend to be those based on regular peer review of referral data and audits at practice level, as well as collaborative working between GPs and specialists."
Jonathan Ashworth, Labour's shadow health secretary, said: "This is a worrying development highlighting how much our NHS is struggling to cope with increase in patient demand and Tory cuts to our health service.
"Patients will rightly be alarmed that millions of pounds is being siphoned off to the private sector to stop people from being referred to hospital.
"Private firms are effectively calling into question clinical decisions which have been made by qualified GPs, simply to cut costs, and patients deserve better."