1. Department of Psychiatry, Loma Linda University, Redlands, CA, USA
2. Department of Statistics, University of California, Riverside, CA, USA
3. Department of Medicine, Loma Linda University Health Care, Loma Linda, CA, USA
4. Health Research Consulting Group, Loma Linda University, Loma Linda, CA, USA
5. Neurosurgery Center for Research, Training, and Education, Loma Linda University, Loma Linda, CA, USA