Association Between Centralization and Outcome for Children Admitted to Intensive Care in Australia and New Zealand: A Population-Based Cohort Study

Objectives: To describe regional differences and change over time in the degree of centralization of pediatric intensive care in Australia and New Zealand (ANZ) and to compare the characteristics and ICU mortality of children admitted to specialist PICUs and general ICUs (GICUs).

Design: A retrospective cohort study using registry data for two epochs of ICU admissions, 2003-2005 and 2016-2018.

Setting: Population-based study in ANZ.

Patients: A total of 43,256 admissions of children aged younger than 16 years admitted to an ICU in ANZ were included. Infants aged younger than 28 days without cardiac conditions were excluded.

Interventions: None.

Measurements and main results: The primary outcome was risk-adjusted ICU mortality. Logistic regression was used to investigate the association of mortality with the exposure to ICU type, epoch, and their interaction. Compared with children admitted to GICUs, children admitted to PICUs were younger (median 25 vs 47 mo; p < 0.01) and stayed longer in ICU (median 1.6 vs 1.0 d; p < 0.01). For the study overall, 93% of admissions in Australia were to PICUs whereas in New Zealand only 63% of admissions were to PICUs. The adjusted odds of death in epoch 2 relative to epoch 1 decreased (adjusted odds ratio [AOR], 0.50; 95% CI, 0.42-0.59). There was an interaction between unit type and epoch with increased odds of death associated with care in a GICU in epoch 2 (AOR, 1.63; 95% CI, 1.05-2.53 for all admissions; 1.73, CI, 1.002-3.00 for high-risk admissions).

Conclusions: Risk-adjusted mortality of children admitted to specialist PICUs decreased over a study period of 14 years; however, a similar association between time and outcome was not observed in high-risk children admitted to GICUs. The results support the continued use of a centralized model of delivering intensive care for critically ill children.