Index Admission Characteristics and All-Cause Readmissions Analysis in Younger and Older Adults with Intracerebral Hemorrhage

Introduction: Intracerebral hemorrhage (ICH) comprises 15-20% of all strokes with debilitating consequences. Data regarding characteristics and outcomes of primary ICH in the young are lacking, given its rarity, making comparisons between younger and older cohorts difficult to perform. Nationally representative administrative databases enable analysis of such rare events. Objective: To determine the baseline characteristics, all-cause readmission rates, and reasons for primary ICH in younger and older adults using a nationally representative database. Methods: A retrospective cohort analysis was performed using the Nationwide Readmissions Database 2013. Validated ICD-9-CM codes identified index ICH admissions, comorbidities, demographics, behavioral risk factors, procedures, and Elixhauser and Charlson Comorbidity indices. We compared "younger"(age ≤ 45 years) and "older"(age > 45) index ICH admissions by weighted 30-day all-cause readmission rates, primary diagnosis code for 30-day readmissions, most common comorbidities during the index hospitalization, and Kaplan-Meier cumulative risk of readmission up to 1 year. Results: Older admissions had higher comorbidity scores and mortality, but both groups had similar total comorbidities. Younger admissions exhibited longer length of stay with more procedures performed. Vascular anomalies (aneurysm 7.2 vs. 4.6% and arteriovenous malformation 5.9 vs. 0.8%) and behavioral risk factors (smoking 26.5 vs. 23.0%, alcohol abuse 6.7 vs. 4.6%, and substance use 13.5 vs. 2.9%) were more prevalent in younger admissions, while older patients had more cardiovascular comorbidities. All-cause 30-day readmission rates (13.1 vs. 13.0%) and 1-year cumulative risk of readmission (log-rank p value 0.7209) were similar. Readmissions in the younger cohort were primarily for neurological conditions, and those in the older cohort were for systemic conditions. Conclusions: Adults <45 years with ICH had similar total comorbidities as older adults but more procedures, longer hospital stay, and more behavioral risk factors. Readmission rates were similar though reasons differed; younger patients were more for neurological reasons than for other systemic causes.