Data from the Parliamentary and Health Service Ombudsman shows that in 2009/10 2,419 complaints were about GPs (17%), 2,411 were about PCTs (17%) and 6,304 (44%) were about acute trusts.
However just 57 of complaints against GPs were accepted for investigation, of which 27 were upheld and reported on.
The Ombudsman’s review of complaint handling, Listening and Learning, warns that local systems will have to improve as GPs take on commissioning responsibility in the next two years.
The two most common reasons for complaints were failings in clinical care and the attitude of staff. A poor explanation or an incomplete response was another reason given for dissatisfaction with the complaints system.
By SHA areas, London received the highest number of complaints per person, followed by the North West – although the South East Coast had the most number of upheld complaints.
Just one PCT – NHS Devon – made it into the top ten most complained-about bodies.
The report backs health secretary Andrew Lansley's calls for complaints to be used more widely to improve services in the NHS.
'We must see complaints as integral to the improvement of the service we provide. Think about it – learning from our mistakes, listening to complaints, comparing what we do, evaluating our performance and constantly seeking to improve our quality,' said Mr Lansley earlier this year.