To examine the proportionate use of critical care resources among children of differing medical complexity admitted to pediatric intensive care units (ICUs) in tertiary-care children's hospitals.

This is a retrospective, cross-sectional study of all children (<19 years of age) admitted to a pediatric ICU between January 1, 2012, and December 31, 2013, in the Pediatric Health Information Systems database. Using the Pediatric Medical Complexity Algorithm, we assigned patients to 1 of 3 categories: no chronic disease, noncomplex chronic disease (NC-CD), or complex chronic disease (C-CD). Baseline demographics, hospital costs, and critical care resource use were stratified by these groups and summarized.

Of 136 133 children with pediatric ICU admissions, 53.0% were categorized as having C-CD. At the individual-encounter level, ICU resource use was greatest among patients with C-CD compared with children with NC-CD and no chronic disease. At the hospital level, patients with C-CD accounted for more than 75% of all examined ICU resources, including ventilation days, ICU costs, extracorporeal membrane oxygenation runs, and arterial and central venous catheters. Children with a progressive condition accounted for one-half of all ICU resources. In contrast, patients with no chronic disease and NC-CD accounted for less than one-quarter of all ICU therapies.

Children with medical complexity disproportionately use the majority of ICU resources in children's hospitals. Efforts to improve quality and provide cost-effective care should focus on this population.