1. Division of Epidemiology, Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla
2. Department of Epidemiology, School of Public Health, San Diego State University, San Diego
3. Department of Pediatrics, University of California, San Diego, La Jolla
4. Division of Rheumatology, Allergy, and Immunology, University of California, San Diego, La Jolla, CA, USA