The Detroit Medical Center says a breach of health information affects more than 1,500 patients seen at one of its facilities in 2015 and 2016.
The health system announced Thursday that a staffing agency contracted by the DMC notified hospital officials that one of the agency's employees provided the information to unauthorized people who weren't affiliated with the DMC organization.
The DMC says letters were sent to 1,529 patients notifying them of the breach, which happened between March 2015 and May 2016.
It notified law enforcement and is cooperating in an ongoing investigation, and it's offering credit monitoring for affected patients.