1. University of Michigan and i3 Drug Safety, Ann Arbor, Michigan, Men's Health Center, Miriam Hospital and Warren Alpert School of Medicine of Brown University, Providence, Rhode Island, University of Virginia, Charlottesville, Virginia, New England Research Institutes, Watertown, Massachusetts, Robert Wood Johnson School of Medicine, Camden, New Jersey, ICON Clinical Research, San Francisco, California, and University of Texas Southwestern Medical Center, Dallas, Texas