P-1926. Once Is Enough, Two Is Too Much: Unraveling Predictors of COVID-19 Readmission among Previously Hospitalized Patients

Abstract Background While risk factors for COVID-19 hospitalization are well characterized, only a few studies investigated those associated with hospital re-admission after SARS-CoV-2 re-infections, since most are focused-on re-admission because of all-causes. Our aim was to identify co-morbidities and other risk factors associated with a second COVID-19 hospitalization. Study flowchart and timeline Methods Administrative database from the Lombardy Welfare Directorate was used to detect patients hospitalized for COVID-19 for a first time between 1st Feb 2020 to 31st Aug 2021. Information on demographic variables, hospital records and drug prescriptions were collected. The population comprised the re-hospitalized individuals, who were readmitted for COVID-19 at least 3 months after their initial hospital admission, likely because of a different SARS-CoV-2 infection and the non-re-hospitalized subjects. Follow-up observation lasted until the re-hospitalization, death or the end of study period. Adjusted hazard ratio (CI, 95%) was performed to assess the association between risk factors and re-hospitalization with a competing risk analysis. Multivariable analysis with competing risk, where death after 3 months is the competing risk for re-hospitalization due to COVID-19. Results From a total of 98,369 patients hospitalized for COVID-19, 25,776 (26.2%) died within three months and 610 (0.6%) were re-hospitalized for a likely new SARS-CoV-2 infection (Figure 1). Re-hospitalized patients were mostly male (61.3%) and were 72.2 years on average. The strongest risks for re-hospitalization in patients with a new episode of COVID-19 were kidney and liver diseases. However, a significant association for this risk was also observed for age, males, immune suppression, cerebro-vascular and cardio-vascular diseases, lung disease, diabetes, and some medications (Table 1). Conclusion We demonstrated that vulnerability due to multimorbidity and chronic conditions, such as kidney and liver disfunction, may diminish the ability to withstand physiological challenges, elevating the risk of re-hospitalization. The fact that the elderly, immune suppressed individuals, or those with chronic conditions may survive an initial hospitalization does not safeguard them from further admissions. We emphasized the importance of targeted interventions and heightened clinical vigilance for these high-risk patient populations. Disclosures All Authors: No reported disclosures