Adverse events are frequent in Neonatal Intensive Care Units' (NICU) patients and account for a high morbidity and mortality. Possible severe adverse events are central line associated bloodstream infections (CLABSI), ventilator and catheter associated adverse events and medication errors. Severity of the patient's outcome after an adverse event can be classified using the National Coordinating Council for Medication Error Reporting and Preventing (NCC MERP) Index for categorizing medication errors.