The researchers at Imperial College London found that in the financial year 2012-2013, 5.8 million A&E attendances in England were preceded by the inability to get a timely appointment at their local surgery.

Tom Cowling told us that there's an annual national survey which is completed by about one million patients, from which they have made their calculations. The report does not establish the patients' clinical need to be in A&E.

"A very small percentage of attempts to get a GP appointment result in a visit to A&E but because there are so many attempts to get a GP appointment - about 350 million a year - this corresponds to a large number of A&E attendances."

Asked whether this supports claims that GPs and NHS are over-stretched, he agrees that a small shift in demand from general practice to A&E can have a big impact on A&E departments.

"There's a current debate around access to general practice, and how we can reduce demand for A&E services - hopefully this analysis can inform that debate and form the foundation for future research on the topic."

It's certainly relevant to the department of health, he says, but more research is needed before recommendations can be made regarding how to improve access and reduce the burden on A&E.

Wtih regard to the cost involved of patients visiting A&E instead of seeing their GP, he says that to an extenet it depends on the outcome of the visit, because it becomes more expensive if the patient ends up being admitted. The average cost per patient is around £50, he told us.