1. Section of Neurosurgery, VA Connecticut Healthcare System, West Haven, Connecticut, and Department of Neurosurgery, Yale University, New Haven, Connecticut
2. Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
3. Section of Outcomes Research, Division of General Internal Medicine, Department of Internal Medicine, University of Cincinnati Medical Center, andCenter for Clinical Effectiveness, Institute for Health Policy and Health Services Research, University of Cincinnati Medical Center, and Veterans Affairs Medical Center, Cincinnati, Ohio
4. Section of Decision Sciences and Clinical Systems Modeling, Division of General Internal Medicine, Department of Medicine, and Center for Research on Health Care, and Division of General Internal Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania