1. Central Brain Tumor Registry of the United States, Hinsdale, Illinois, USA
2. Department of Medicine, Section of Epidemiology and Population Sciences, Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas, USA
3. Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
4. Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
5. Cleveland Center for Health Outcomes Research, Cleveland, Ohio, USA