Discovery in a civil case is not limited to trial evidence. In fact, the rules in most jurisdiction allow discovery of anything that is reasonably calculated to lead to the discovery of admissible evidence. In most medical malpractice cases, this means a list of all prior professional negligence claims (no matter the outcome). These prior cases often lead to a goldmine of useful information.

Here is the link to the story about NY prisoners seeking to obtain such a list from the healthcare providers in the jail.

Prisoners Suing Bureau of Prisons for Bad Care Want to Discover List of Cases Against Doctors