1. Heart and Vascular Institute, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA.
2. Department of Epidemiology, School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
3. Department of Behavioral and Community Health Sciences, School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
4. Department of Epidemiology, School of Public Health, Emory University, Atlanta, Georgia, USA.
5. Division of Research, Kaiser Permanente Northern California, Oakland, California, USA.
6. Department of Preventive Medicine, Rush University Medical Center, Chicago, Illinois, USA.