Abstract 041: Readmission Rates and Etiologies among Patients with Intracerebral Hemorrhage: A United States Nationwide Analysis
Authors: Laswi Ibrahim , Arabi Maryam , Al‐Najjar Yousef , Dargham Soha , Jerdi Salman Al , Khalil Charbel Abi 
Published: March 2024

Introduction
Nontraumatic Intracerebral Hemorrhage (ICH) is the second most prevalent type of stroke worldwide and is strongly linked with severe disability and mortality. Survivors of ICH have a high risk of all‐cause readmission. Understanding characteristics of readmitted patients and etiologies of readmission may provide a framework for risk stratification and readmission prevention.

Methods
We identified patients with a primary diagnosis of ICH (ICD‐10 code: I61.x) from 2016‐2019 using the Nationwide Readmission Database (NRD). The difference in days between the index admission and the readmission was used to identify patients who were readmitted within 30 and 90 days. The primary diagnosis of the readmission was used to identify the etiology of readmission. Data was weighted to allow for representative nationwide estimates.

Results
A total of 260,854 patients were admitted with a primary diagnosis of ICH between 2016‐2019. The mean age of the cohort was 68.49 years, with 52.6% being male. The 30‐day readmission rate was 7.68% while the 90‐day readmission rate was 12.73%. There was a small but significant increase in 90‐day readmission rates from 2016 to 2019 (12.61% vs 12.93%, p=0.05), but no significant increase in 30‐day readmission rates (7.10% vs 7.72%, p=0.870). Around 60% of 90‐day readmissions occurred within the first 30 days. Patients readmitted within 30 days and within 90 days, compared to those not requiring readmission, were more likely to be younger (68 and 68.1 vs 68.53 years) and male (54.87% and 53.92% vs 52.41) (p<0.001). They also had a higher prevalence of diabetes (32.43% and 32.82% vs 28.42%), dyslipidemia (44.57% and 44.81% vs 41.41%), obesity (13.19% and 13.64% vs 12.03%), prior TIA/ischemic stroke (6.46% and 6.52& vs 5.60%), PVD (6.17% and 6.27% vs 4.88%), coronary artery disease (20.52% and 20.52% vs 17.83%), chronic renal failure (20.52% and 22.21% vs 17.83%), and heart failure (15.98% and 15.87% vs 12.47%) (p<0.001 for all). The most common etiologies of 30‐day readmissions were cardiovascular (38.55%), infectious (12.57%), and neurological (6.96%). In contrast, the most common etiologies of 90‐day readmissions were cardiovascular (36.21%), infectious (12.42%), and respiratory (6.92%).

Conclusion
There was a small but significant increase in the rate of 90‐day readmissions among patients with ICH between 2016 and 2019. Patients requiring readmission within 30 and 90 days had a significantly higher prevalence of vascular risk factors and related comorbidities. While cardiovascular and infectious conditions were the most common etiologies of readmission among both groups, neurologic conditions contributed more to 30‐day readmissions, while respiratory conditions made up a higher proportion in etiologies of 90‐day readmission. This suggests that further neurologic injury, potentially related to the primary ICH, occurred relatively early on in the course of recovery. Our analysis suggests a possible role of vascular risk factor modification in preventing readmissions after ICH. However, further research is required to validate this hypothesis and to identify other potentially modifiable risk factors.