By Nick Triggle
Health reporter, BBC News
NHS Direct is referring on too many patients to GPs and emergency services, putting strain on the system, doctors and ambulance crews say.
NHS Direct was set up in 1997
They claim to get urgent referrals when patients have minor problems, such as sprains and high temperatures.
The British Medical Association called for an inquiry, saying the service "erred too much on the side of safety".
NHS Direct refers on two thirds of callers - half as urgent or emergencies - but wants to deal with more itself.
The service receives about 500,000 calls a month.
According to latest figures, some 34% are dealt with by NHS Direct, just short of government targets.
Another 34% of patients are told to contact other services such as dentists, GPs, pharmacies or walk-in centres.
A further 32% are referred as urgent or emergency cases and are told to see a GP immediately or sent to hospital - in line with government targets.
Dr Mark Reynolds, GP out-of-hours spokesman for the NHS Alliance and a member of the government's advisory group which oversaw the formation of 24-hour phone service, said the targets were too lenient.
And he said: "NHS Direct is too cautious.
"They refer patients on as urgent or emergency when doctors doing out-of-hours or in A&E would not recognise them as such.
"We have had things like moderate temperatures or diarrhoea and vomiting referred as urgent.
"It puts strain on the system as it means we have to see the patients quickly, which could be a risk to patients who are real emergencies."
And Dr Reynolds, who is chief executive of On Call Care, which provides out-of-hours GP care to parts of Sussex and Kent, added: "It also means NHS Direct is delaying people's care.
"Half of the referrals we get from NHS Direct are treated over the phone by our nurses. Why can't NHS Direct treat more themselves?
"Two of the aims of NHS Direct when it was set up was to relieve pressure on services and simplify access. It has not done either of these."
Jonathan Fox, of the Association of Professional Ambulance Personnel, said union members had had patients referred to them with nothing more than a sprain.
He added: "The number of referrals are too high and in some cases unnecessary.
"I would like to see the Audit Commission or one of the other watchdogs have a look at how this could be reduced."
Hamish Meldrum, chairman of the British Medical Association's GPs committee, added: "One does have concerns when you see two thirds do get referred on somewhere else.
"That does not compare well with other services. The evidence we have is that NHS Direct errs too much on the side of safety.
"I would like to see a full independent review."
Helen Young, clinical director of NHS Direct, said the service was looking to increase the number of calls dealt with in-house.
"It is something we are looking to do, but we do have some arrangements with GP out-of-hours providers that mean we have to pass on all the calls we get.
"As we do not see patients face-to-face we have to operate with a degree of caution."
A Department of Health spokeswoman said: "NHS Direct will continue to work to ensure that only appropriate callers are referred but it is important that patient safety is not compromised."
And NHS Direct also received the support of A&E doctors. Martin Shalley, of the British Association of Emergency Medicine, said: "We do not have a problem with their referrals. It is important they operate safely."