1. Johns Hopkins Children's Center, Baltimore, MD, United States; Patient Safety Translational Research Centre, Imperial College London, UK
2. Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
3. University of North Carolina, Chapel Hill, NC, United States
4. Imperial College London, UK
5. Patient Safety Translational Research Centre, Imperial College London, UK; Centre for Health Technology and Services Research/Department of Community Medicine, Information and Decision in Health, University of Porto, Portugal