Maayke Hunfeld

204 Chapter 7 Methods Study design and participants This prospective study was performed in children admitted to the paediatric intensive care unit (PICU) of Erasmus MC-Sophia Children’s Hospital, the single tertiary-care University children’s hospital providing health care to children in the southwest of The Netherlands (referral area 4 million inhabitants, 25% of the Dutch population). The Erasmus MC Ethical Review Board approved the study protocol (MEC-2019-0259). In accordance with the Dutch law, signed informed consent was not required at moment of inclusion We included children (0-17 years) who experienced OHCA between 2012 and 2017 and survived to hospital discharge. OHCA was defined as unresponsiveness with absent palpable pulse, no signs of life, or healthcare provider perceived need for chest compressions for at least one minute (7) . Exclusion criteria were a pre-arrest PCPC score > 3 and children diagnosed with a neurodegenerative disease. Data collection As part of standard care children were invited to our multidisciplinary follow-up program at the outpatient clinic 3-6 and 24 months post-OHCA. Functional outcomes were assessed by an experienced paediatric neurologist (MH) and paediatric intensivist (CB) through a semi-structured interview with children and their parents/ caregivers and through physical and neurological exams. When no follow-up visit took place, these outcomes, if available, were collected from notes in the patient records (records of hospital visits with other physicians). Neuropsychological outcomes were assessed by an experienced psychologist. If neuropsychological testing was performed elsewhere, results were retrieved after parental consent. Demographical and OHCA variables The following variables were retrospectively collected from ambulance registration forms and in hospital electronic health records: 1. Baseline patient characteristics (e.g. gender, age, socioeconomic status (SES) parents, pre-arrest PCPC), 2. OHCA and post- OHCA characteristics (aetiology, first monitored rhythm, bystander cardiopulmonary resuscitation (CPR), duration CPR, first pH and lactate), and 3. Medical outcome