1. From the Departments of Emergency Medicine and Critical Care Kaiser Permanente Oakland Medical Center Oakland CA USA
2. the Division of Research Kaiser Permanente Northern California Oakland CA USA
3. the Department of Emergency Medicine Kaiser Permanente San Leandro Medical Center San Leandro CA USA
4. the Department of Emergency Medicine Kaiser Permanente Oakland Medical Center Oakland CA USA
5. the Department of Emergency Medicine Kaiser Permanente South Sacramento Medical Center South Sacramento CA USA
6. the Department of Emergency Medicine Kaiser Permanente Santa Clara Medical Center Santa Clara CA USA
7. the Department of Emergency Medicine Kaiser Permanente Walnut Creek Medical Center Walnut Creek CA USA
8. the Department of Emergency Medicine Kaiser Permanente South San Francisco Medical Center South San Francisco CA USA
9. the Department of Emergency Medicine Kaiser Permanente Roseville Medical Center Roseville CA USA
10. the Department of Emergency Medicine Kaiser Permanente San Francisco Medical Center San Francisco CA USA
11. the University of California San Diego School of Medicine San Diego CA USA
12. the Department of Emergency Medicine Kaiser Permanente Sacramento Medical Center Sacramento CA USA
13. and the Department of Emergency Medicine Kaiser Permanente San Rafael Medical Center San Rafael CA USA