1 Doctoral Program in Healthcare, Faculty of Nursing, Physiotherapy and Podiatry, University Complutense of Madrid, Madrid, Spain.
2 Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine, Palo Alto, CA, United States.
3 Head of Service, Surgery and Urology Pediatric Unit, University Hospital 12 Octubre of Madrid, Madrid, Spain.
4 Department of Radiology, Rehabilitation and Physiotherapy, Faculty of Nursing, Physiotherapy and Podiatry, University Complutense of Madrid, Madrid, Spain.
5 IdISSC, Madrid, Spain.
6 Center for Child Health, Behavior and Development, Seattle Children's Research Institute, Seattle, WA, United States.
7 Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Seattle, WA, United States.