From a site known as the insurancejournal.com:
The majority of medical malpractice claims in a study of seven states were closed without any compensation paid to those claiming a medical injury, the Justice Department's Bureau of Justice Statistics (BJS) reported. Go here for the abstract.
BJS conducted a study of medical malpractice insurance claims that were closed from 2000 through 2004 in Florida, Illinois, Maine, Massachusetts, Missouri, Nevada and Texas. These states were identified as having comprehensive medical malpractice insurance claims databases, some of which extended back to the early 1990s.
You can find the rest here.