New Morbidities During Critical Illness and Associated Risk of ICU Readmission: Virtual Pediatric Systems Cohort, 2017-2020.

Objectives: To describe change in Functional Status Scale (FSS) associated with critical illness and assess associated development of new morbidities with PICU readmission.

Design: Retrospective, cross-sectional cohort study using the Virtual Pediatric Systems (VPS; Los Angeles, CA) database.

Setting: One hundred twenty-six U.S. PICUs participating in VPS.

Subjects: Children younger than 21 years old admitted 2017-2020 and followed to December 2022.

Interventions: None.

Measurements and main results: Among 40,654 patients, 86.2% were classified as having good function or mild dysfunction before illness. Most patients did not have a change in their FSS category during hospitalization. Survival with new morbidity occurred most in children with baseline good/mild dysfunction (8.7%). Hospital mortality increased across categories of baseline dysfunction. Of 39,701 survivors, 14.2% were readmitted within 1 year. Median time to readmission was 159 days. In multivariable, mixed-effects Cox modeling, time to readmission was most associated with discharge functional status (hazard ratio [HR], 5.3 [95% CI, 4.6-6.1] for those with very severe dysfunction), and associated with lower hazard in those who survived with new morbidity (HR, 0.7 [95% CI, 0.6-0.7]).

Conclusions: Development of new morbidities occurs commonly in pediatric critical illness, but we failed to find an association with greater hazard of PICU readmission. Instead, patient functional status is associated with hazard of PICU readmission.