Objectives:Our study aimed to assess differences in the susceptibility to severe acute illness in children with and without chronic health conditions treated in a pediatric intensive care unit (PICU). Patients and methods:Data on age,gender,need for ventilator support,length of stay,as well as other parameters for the Paediatric Index of Mortality (PIM2) score were collected.Data were analyzed and compared across three patient groups:those with a neurodevelopmental disability,those with a chronic condition other than a neurodevelopmental disability,and those with no chronic condition. Reasons for admission of patients were classified according to the Australia and New Zealand Paediatric Intensive Care Registry (ANZPIC Registry)-diagnostic codes. In the multidisciplinary,seven-bed,level IPICU of the Split University Hospital,the admission data were collected prospectively for 591 consecutively admitted patients aged ≤18 years. Results:Patients with a neurodevelopmental disability had a significantly higher rate of respiratory-related admissions compared to patients with other chronic health conditions and those with no chronic condition (χ2=33.72,P< 0.001). There was a significant difference in the age at admission (f=6.04,P=0.003),median length of stay (f=7.94,P< 0.001),need for ventilation during the first hour of admission(χ2=14.74,P< 0.001) and PICU mortality (χ2=9.91,P=0.007)-of patients with neurodevelopmental disabilities,compared to the other two groups of patients. Conclusion:Children with neurodevelopmental disabilities are more susceptible to acute illness compared to children with other chronic health conditions and those with no chronic condition. Objectives: Our study aimed to assess differences in the susceptibility to severe acute illness in children with and without chronic health conditions treated in a pediatric intensive care unit (PICU). Patients and methods: Data on age, gender, need for ventilator support, length of stay, as well as other parameters for the Pediatric Index of Mortality (PIM2) score were collected. Data were analyzed and compared across three patient groups: those with a neurodevelopmental disability, those with a chronic condition other than a neurodevelopmental disability, and those with no chronic condition. Reasons for admission of patients were classified according to the Australia and New Zealand Pediatric Intensive Care Registry (ANZPIC Registry) -diagnostic codes. In the multidisciplinary, seven-bed, level IPICU of the Split University Hospital, the admission data were collected prospectively for 591 consecutively admitted patients aged ≤ 18 years. Results: Patients with a neurodevelopmental disability had a significantly higher rate of respiratory-related admissions compared to patients with other chronic health conditions and those with no chronic conditions (χ2 = 33.72, P <0.001). There was a significant difference in the age at admission (f = 6.04, P = Need for ventilation during the first hour of admission (χ2 = 14.74, P <0.001) and PICU mortality (χ2 = 9.91, P = 0.007) -of patients with neurodevelopmental disabilities, compared to the other two groups of patients. Conclusion: Children with neurodevelopmental disabilities are more susceptible to acute illness compared to children with other chronic health conditions and those with no chronic condition.