Ministers want to see polyclinics set up in England
Average-sized GP surgeries are just as good as "super-surgeries" at providing extra services, a study suggests.
Ministers in England have asked health chiefs to create a network of polyclinics to provide extra care, such as diabetes clinics and minor surgery.
But a Kent-based GP's study of 384 practices found no difference between the range of extra services offered by standard surgeries and polyclinics.
The government said polyclinics would provide a valuable service to patients.
Every NHS trust in the country has been told to set up at least one polyclinic, with a whole network being created in London.
Ministers believe the super-surgeries are the best way of moving care out of hospitals and into the community.
But the study by Dr Hendrik Beerstecher, who specialises in research, found large surgeries already operating were no better at providing the specialist care the government is so keen on.
He looked at the range of extra services, beyond the average package of GP care, being provided by a range of different-sized practices up to ones serving a population of more than 30,000.
He found small surgeries - classed as having fewer than 6,300 patients - tended to provide less diverse extra services.
But once the threshold of 6,300 was reached - the average size for a practice in England - there was little difference no matter how big the surgery was.
On average, these had between 10 and 11 extra services.
Dr Beerstecher, who is not a member of the British Medical Association, the doctor's trade union body which has campaigned against polyclinics, said: "I am not sure why the government is pushing ahead with polyclinics.
"As the study shows, there is no evidence that they provide more services so why are we having them set up all across the country?"
Dr Richard Vautrey, the deputy chairman of the BMA's GPs committee, said: "This proves what we have been saying all along - that we should not be rushing headlong into setting polyclinics up.
"GPs have always been innovative. You do not need a big surgery for this to happen."
The Department of Health said it was investing £250 million in new services to improve access to GP services.
"This includes 152 GP health centres, open 8am-8pm, seven days a week, which can be used by any member of the public on top of, not instead of, their existing GP surgery," a spokeswoman said.
"We are not imposing super surgeries or replacing existing services.
"Patients have told us that they want greater choice and flexibility in primary care. This will be a valuable service for patients and families across the country, particularly if they want to see a GP when they are away from home or at times that their local GP practice is not open."