1. Division of Neurosurgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina
2. Department of Bioinformatics and Biostatistics
3. Center for Neurosurgical Outcomes Research, Maxine Dunitz Neurosurgical Institute, Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, California
4. Department of Neurosurgery, University of Louisville, Louisville, Kentucky