Risks for death after admission to pediatric intensive care (PICU)-A comparison with the general population.

Objective/aim: The aim of the study was to quantify excess mortality in children after admission to a Pediatric Intensive Care Unit (PICU), compared to the age and sex matched general Swedish population.

Design: Single-center, retrospective cohort study.

Setting: Registry study of hospital registers, a national population register and Statistics Sweden.

Patients: Children admitted to a tertiary PICU in Sweden in 2008-2016.

Interventions: None.

Main Results: In total, 6,487 admissions (4,682 patients) were included in the study. During the study period 444 patients died. Median follow-up time for the entire PICU cohort was 7.2 years (IQR 5.0-9.9 years). Patients were divided into four different age groups (0-28 d, > 28 d -1 yr, > 1-4 yr, and > 4 yr) and four different risk stratification groups [Predicted Death Rate (PDR) intervals: 0-10%, > 10-25%, > 25-50%, and > 50%] at admission. Readmission was seen in 929 (19.8%) patients. The Standardized Mortality Ratios (SMRs) were calculated using the matched Swedish population as a reference group. The SMR for the entire study group was 49.8 (95% CI: 44.8-55.4). For patients with repeated PICU admissions SMR was 108.0 (95% CI: 91.9-126.9), and after four years 33.9 (95% CI: 23.9-48.0). Patients with a single admission had a SMR of 35.2 (95% CI: 30.5-40.6), and after four years 11.0 (95% CI: 7.0-17.6). The highest SMRs were seen in readmitted children with oncology/hematology (SMR = 358) and neurologic (SMR = 192) diagnosis. Children aged >1-4 years showed the highest SMR (325). In PDR group 0-10% children with repeated PICU admissions (n = 798), had a SMR of 100.

Conclusion: Compared to the matched Swedish population, SMRs were greatly elevated up to four years after PICU admission, declining from over 100 to 33 for patients with repeated PICU admissions, and from 35 to 11 for patients with a single PICU admission.