The chairwoman of the Atlanta-based Grady Memorial Hospital board has become the center of controversy for taking on the hospital CEO role while postponing a management change some believe could lead to her ouster. Pamela Stephenson was named chief executive of the hospital in late January 2008, and said it would only be on an interim basis. But there are suggestions she is pressing to become Grady's permanent chief--a committee of Grady board members has been named to negotiate a contract for Stephenson.