Patient safety has emerged as the biggest area of concern in complaints that are handled by the Healthcare Commission.

The commission, which reviews complaints where patients have been unhappy with a trust's response, has revealed that 24 per cent of these complaints from August 2006 to July 2007 concerned issues of safe and effective practice.

Its Spotlight on Complaints report states: "Patients felt that the care and treatment they had received was not of a sufficiently high standard, and there was actual or potential risk of harm to the patient or others."

Other frequent themes included communication, complaints handling, patient experience, clinical treatment and appointments being delayed or cancelled.

The biggest proportion of complaints (38 per cent) were related to primary care, followed by the acute sector (34 per cent), foundation trusts (18 per cent), mental health trusts (7 per cent), ambulance trusts (1 per cent) and others (1 per cent).