The NHS has developed a "widespread culture of fear", reports have claimed.
The findings were obtained by centre-right think tank Policy Exchange, with one report accusing the Department of Health of being more interested in costs than clinical quality.
Policy Exchange used the Freedom of Information Act to obtain the documents that had been commissioned by the Government. They were prepared for the Department of Health in 2008 as the Government undertook a major restructuring of NHS regulation.
One report, Quality Oversight In England, by the Joint Commission International, identified "the pervasive culture of fear in the NHS and certain elements of the Department for Health".
Another, by the Institute of Healthcare Improvement, said the "NHS has developed a widespread culture more of fear and compliance, than of learning, innovation and enthusiastic participation in improvement".
Health experts RAND raised "concern that the Department of Health is more interested in costs than clinical quality".
The revelations follow high-profile failings in care at health trusts in Tunbridge Wells, Mid Staffordshire and Basildon.
Henry Featherstone, from the Health and Social Care Unit at Policy Exchange, said: "The reports detail a frightening catalogue of flaws in patient safety procedures - and Government has dragged its feet over implementing a robust system of inspection and improvement, even after these flaws have been highlighted in the strongest possible terms.
"Under a proper system of inspection and oversight, coupled with a continual process of performance improvement, hundreds - if not thousands - of lives would be saved."
A Department of Health spokeswoman said: "We have set up and work alongside the National Patient Safety Agency to encourage medical staff to report and learn from incidents even when no harm was caused to the patient. Every death or serious injury due to mistakes in medical care must be investigated and the lessons must be learned and acted upon."
