1. Centre for Health Economics, University of York, York, United Kingdom
2. Division of Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, California
3. Centre for Statistical Methodology, London School of Hygiene and Tropical Medicine, London, United Kingdom
4. Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom
5. Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, United Kingdom
6. Department of Anesthesiology, Perioperative and Pain Medicine, Division of Critical Care, Boston Children’s Hospital, Boston, Massachusetts
7. Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts