SESSION TITLE: Pulmonary Manifestations of Systemic Disease Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Acute Chest Syndrome (ACS) is a pulmonary sequela of Sickle Cell Disease (SCD), which is a frequent cause of hospitalization, readmissions, and mortality. This study aims to illuminate key predictors of 30-day readmission, a commonly used quality metric, and examine healthcare utilization and burden of Acute Chest Syndrome in the US. METHODS: This is a retrospective cohort study using the 2016 and 2017 National Readmission Database. Inclusion criteria are the following: patient age >2, urgent admissions with principal ICD-10 codes for ACS. Readmission is defined as the first admission to any hospital for any non-trauma diagnosis within 30 days of the index admission. The primary outcome was all-cause 30-day readmissions. Secondary outcomes were readmission mortality rate, common reason for readmission, resource utilization, and factors that are predictive of hospital readmission. Independent risk factors for readmission were identified using multivariate cox regression analysis. RESULTS: The total number of index ACS admissions was 16,451, of which 3,398(20.7%) were readmitted within 30 days. The top causes of readmission were as Hb-ss with crisis (54.7%), Hb-ss with ACS (13.8%), sickle-cell/Hb-c with Crisis (25.5), Sickle-cell thalassemia with crisis (2.3%), Pneumonia, Unspecified organism (2.2%), Sepsis, Unspecified Organism (2.1%). The in-hospital mortality rate for readmitted patients was approximately lower than that in index admissions (0.1% vs. 0.5%, p<0.001). Morbidity and resource utilization were higher in Index admission compared to readmission, length of stay (LOS) (6.24 vs 5.87 days, p<0.002) and mean cost of hospitalization ($13,564 vs $10,944 , p <0.001), respectively. The total in-hospital economic burden associated with readmission was $ 37 million. Independent predictors of higher 30-day readmissions were age group 18-30 (Adjusted Hazard ration(aHR)2.37,p<0.01), 30-40 (aHR-2.33,p<0.01), 40-50 (aHR-2.15,p<0.01),50-65 (aHR-1.48,p<0.01), higher Charlson Comorbidity burden (aHR-1.44,p-0.009), COPD (aHR-1.43,p-0.01), Depression (aHR-1.30,p-0.009), Chronic pain Syndrome (aHR-1.48,p<0.001), discharge against medical advice (aHR-1.60,p-0.001). In contrast, independent predictors of lower 30-day readmissions were private insurance recipients(aHR-0.83,p-0.04) and uninsured(aHR-0.53,p-0.01), higher household income(aHR-0.78,p-0.01), blood transfusion recipient during index admission(aHR-0.72,p-0.001) CONCLUSIONS: We found that 20.7% of hospitalized pts with ACS were readmitted within 30 days. These readmissions have a significant burden on the US Healthcare system. We identified risk factors associated with 30-days readmission. CLINICAL IMPLICATIONS: Patients at risk for readmission need to be targeted to improve outcomes and ACS care quality. DISCLOSURES: No relevant relationships by Shiva Arjun, source=Web Response No relevant relationships by Si Li, source=Web Response No relevant relationships by Palakkumar Patel, source=Web Response No relevant relationships by Pranavi Patel, source=Web Response No relevant relationships by Yichen Wang, source=Web Response