(340) TISS-28 Scores to Predict Length of Stay in Critically Ill Children With Complex Chronic Conditions

Introduction: Admissions to the pediatric intensive care unit (PICU) for complex chronic conditions (CCC) patients has increased rapidly. CCC patients have worse outcomes including longer length of stay (LOS) compared to those without CCC. Obtaining large-scale data to assess outcome variations and identify those at high risk for longer LOS is challenging for CCC patients due to their heterogeneity. An approach is to utilize severity of illness scores. There is no validated score available for CCC patients. Therapeutic Intervention Scoring System-28 (TISS-28) is a validated tool used in medically complex adults. The goal of this study was to determine the utility of TISS-28 as an outcome predictor for PICU LOS in CCC pediatric patients as well as compare it to a standard outcome measure, Pediatric Risk of Mortality-3 (PRISM-3).

Methods: This was a retrospective cohort study conducted in a 24-bed PICU in a quaternary care children’s hospital. All patient encounters ≤ 18 years of age admitted to the PICU between January 1, 2022, and December 31, 2022, who met criteria for CCC according to the Feudtner classification system were included. Patients were excluded if their PICU stay was < 24 hours or if they were readmitted within 24 hours. TISS-28 and PRISM-3 scores were calculated for each patient upon PICU admission. Primary outcome was PICU LOS. Linear regression models were used to assess the predictive capabilities of TISS-28 and PRISM-3 scores for PICU LOS.

Results: Among 1767 encounters, 656 (37%) were identified as CCC. After all inclusion criteria were met, 440 CCC patients were enrolled. Median PRISM-3 was 1.17 (1.17-3.4) and median TISS-28 was 23.5 (20-27) for all enrolled patients at PICU admission. Linear regression analysis revealed that TISS-28 significantly predicted PICU LOS (p= < 0.001) while PRISM-3 did not (p=0.348).

Conclusions: TISS-28 may be a useful tool for assessing severity of illness and predicting LOS in CCC patients who are at risk for worse outcomes in the PICU compared to our current standard. TISS-28 data could lead to improvement in care and a more equitable healthcare system for this marginalized population. Larger prospective studies are necessary to validate the role of TISS-28 in CCC pediatric patients.