The best academy chains are outperforming other state-funded schools, while others are failing to raise standards, research has revealed.

The Chain Effects report from the Sutton Trust shows disadvantaged students are improving faster than the national average in 18 of 31 chain academies, but warns that weaker academy chains are underperforming when compared with mainstream schools.

On the core five good GCSEs measure, five chains improved significantly more than the national average between 2011 and 2013. These were Barnfield, The City of London Corporation, the David Ross Education Trust, the Diocese of Salisbury, and Leigh Academies Trust.

In all of these chains, the improvement in the proportion of disadvantaged students achieving five good grades in 2013 was 4.5 times the average rate in all mainstream schools. However, the report shows that some academies used vocational qualifications equivalent to GCSEs to achieve these results, which will be disallowed from the 2014 performance tables.

Conor Ryan, director of research at the Sutton Trust, said: ‘When academies were first established more than a decade ago, their primary purpose was to lift standards for disadvantaged pupils in areas where schools had been failing.

‘Our report shows that some chains are succeeding well in meeting this goal but others are failing to do so, particularly on those measures against which all schools are increasingly judged. Of course, it takes time to turn around failing schools, so we have also highlighted those schools that are showing rapid improvement.

‘However, it is vital that Ofsted routinely inspects academy chains and there is much stronger action taken where chains are consistently underperforming.’

Professor Becky Francis, one of the researchers of the report from King’s College London, added: ‘Some chains are securing excellent results for their disadvantaged pupils across a whole range of measures, showing what can be achieved her by experienced chains with a planned approach to growth.

‘Their work should be recognised and applauded. But others are doing badly on important measures, and risk becoming part of the problem rather than the solution for their disadvantaged pupils. The Government needs to increase transparency and scrutiny of academy chains.’