1. Pediatric Headache Program, Department of Neurology, University of California, San Francisco
2. Department of Epidemiology and Biostatistics, University of California, San Francisco
3. Department of Epidemiology and Biostatistics, University of California, San Francisco3Department of Medicine, University of California, San Francisco
4. Pediatric Headache Program, Department of Neurology, University of California, San Francisco4National Institute of Health Research-Wellcome Trust Clinical Research Facility, King’s College London, United Kingdom
5. Department of Epidemiology and Biostatistics, University of California, San Francisco3Department of Medicine, University of California, San Francisco5San Francisco Coordinating Center, California Pacific Medical Center Research Institute, University of California, San Francisco