1. Department of Epidemiology and Biostatistics University of South Carolina Columbia South Carolina USA
2. Center for Child Health, Behavior and Development Seattle Children's Research Institute Seattle Washington USA
3. Department of Pediatrics University of Washington Seattle Washington USA
4. Fred Hutchinson Cancer Research Center Seattle Washington USA
5. School of Economics Sapienza University of Rome Rome Italy
6. Department of Biostatistics and Data Sciences Wake Forest School of Medicine Winston Salem North Carolina USA
7. Department of Epidemiology University of Colorado School of Medicine Aurora Colorado USA
8. Division of Epidemiologic Research, Department of Research & Evaluation Kaiser Permanente Southern California Pasadena California USA