[1] Stanford Univ, Div Primary Care & Populat Hlth, Sch Med, Stanford, CA 94305 USA
[2] Stanford Univ, Sch Med, Stanford, CA USA
[3] Baystate Med Ctr, Med & Pediat, Springfield, MA USA
[4] Stanford Univ, Sch Med, Dept Neurol & Neurol Sci, Stanford, CA USA
[5] Stanford Univ, Sch Med, Stanford, CA USA
[6] Univ Calif Los Angeles, Hlth Policy & Management, Los Angeles, CA USA
[7] Lucile Packard Childrens Hosp, Stanford Childrens Hlth, Stanford, CA USA
[8] Stanford Univ, Sch Med, Dept Bioinformat, Stanford, CA USA
[9] Stanford Univ, Sch Med, Dept Neurol & Neurol Sci, Stanford, CA USA