As many as one in 10 patients admitted to NHS hospitals endure errors in their treatment, according to a new study.

Medical accidents and errors contribute to the deaths of 72,000 people a year, and they are directly blamed for 40,000.

They also cost the NHS £2 billion in increased hospital stays, according to the audit by the healthcare research group Dr Foster.

Roger Taylor, research director of Dr Foster, said: "Compared with the transport industry, the number of errors causing very high levels of death is extraordinary."