Research conducted by the Centre for Health Economics at the University of York found considerable variations in how well SHAs in England spent NHS cash.
South West SHA was the most efficient region at 5.3 per cent above the national average for productivity.
But East Midlands SHA was 6.6 per cent less productive than the national baseline, according to data from 2007/8.
The SHA could deliver the same level of care for £600 million less each year if it matched South West SHA's efficiency, the researchers said.
Overall, the NHS could save almost a fifth of its £20 billion efficiency target if all SHAs were as productive as the South West SHA, the report found.
A DoH spokeswoman said the findings 'reiterate the need to tackle the issue of productivity in the NHS'. The department expects GP commissioning to help improve efficiency by redesigning services based on local need and limiting bureaucracy.
But GPC deputy chairman Dr Richard Vautrey said: 'While I am sure GP-led consortia will strive to learn from best practice around the country, making efficiency savings wherever possible, it is unreasonable to think that variation will be eliminated completely.'
The report compared inputs - spend on staff, capital resources and services - with outputs - care outcomes and waiting times. General practice was not included in the analysis due to a lack of data. Researchers also accounted for patient type, quality of care and resource costs so these did not affect the findings.
They found productivity was also below average in South Central, West Midlands and Yorkshire & Humber SHAs. East of England, London, North East and North West SHAs came out above the baseline.