The Chairman of the Healthcare Commission has said there is still "a great deal to do before the NHS can be confident that the care patients receive is as safe as it can be."
Sir Ian Kennedy said that mistakes need to be reported and learnt from in order for the NHS to grow stronger and that this process should be "internalised in its DNA".
According to the Commission, medical errors occur in primary care up to 80 times per 100,000 consultations (up to 600 errors a day). Up to 20% of these are thought to cause harm.
Of this total, just 0.3% of incidents occurring in England and Wales in 2007/08 were from general practice, but the largest number of complaints, 38% in 2006/07, reviewed by the Commission were related to primary care.
Sir Ian added: "Information about things such as missed diagnoses or late diagnoses won't show up in any register of untoward events because there's no incident, there's just a black hole."
He said that, although the safety of patients has risen up the government's and the NHS's agendas, "we are a long way from an NHS which systematically and hungrily examines its performance and reinforces safe practice."