1. School of Medicine, Georgetown University, Washington, District of Columbia, USA;
2. Bowers Neurosurgical Frailty and Outcomes Data Science Lab, Albuquerque, New Mexico, USA;
3. Topiwala National Medical College, Mumbai, India;
4. Department of Neurosurgery, University of New Mexico Hospital, Albuquerque, New Mexico, USA;
5. Department of Neurosurgery, Westchester Medical Center & New York Medical College, Valhalla, New York, USA;
6. Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA;
7. Center for Health Equity Research and Promotion, Virginia Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, USA;
8. Wolff Center at UPMC, Pittsburgh, Pennsylvania, USA