The Nuffield Trust report said emergency admissions have increased by 12% between 2004/5 and 2008/9, with the number of short-stay admissions – patients admitted for one day or less – rising by a similar amount.
The report said this indicates that the clinical threshold for acute admissions has been lowered, with patients with less severe conditions being admitted.
It said local clinicians and managers should look to improve how clinical decisions to admit patients to hospital are made, for example through greater use of primary care physicians in A&E and/or greater use of consultants to decide on admission.
Nuffield Trust director Dr Jennifer Dixon said: 'Our hospitals are over-heating and are on an unsustainable path in which they are treating patients at great cost to the NHS and to patients themselves.
'This cost could be avoided by preventing ill health through better care by GPs, community care services or social care, and better co-ordination of care between doctors in hospital and general practice.'
Nigel Edwards, acting chief executive of the NHS Confederation, said: ‘Hospital is often the right place for sick patients to be but we know that for many there are better, more convenient and more cost effective alternatives to hospital admission.
‘Difficult decisions on service reorganisation will be needed but, by getting all those involved in urgent and emergency care, from GP practices to ambulances and pharmacies, working together to ensure that care is given in the right place at the right time, the NHS will be able to both offer better care and save money for the taxpayer.’