Characteristics and outcomes in patients with in-hospital stroke: Japan stroke data bank

Purpose: We aimed to clarify the clinical characteristics and outcomes of patients with in-hospital onset ischemic stroke (IOS) compared with those in patients with community-onset ischemic stroke (COS). Methods: Patients from the Japan Stroke Data Bank, a hospital-based multicenter prospective registry, who were diagnosed with acute ischemic stroke (AIS) within 24 h of onset between January 2001 and December 2020 were included in this study. We assessed favorable outcomes at discharge corresponding to a modified Rankin Scale (mRS) score of 0–2, unfavorable outcomes corresponding to an mRS score of 5–6, and mortality. We also examined trends in these outcomes at 4-year intervals over a period of 20 years. Results: Of the 100,865 patients analyzed, 2979 had IOS (1416 women, mean age 77 ± 12 years) and were older than those with COS (n = 97,886; 39,110 women, mean age 74 ± 12 years). Multivariate analysis revealed that younger age, higher premorbid mRS score, absence of stroke history, normotension, congestive heart failure, coronary artery disease, chronic kidney disease, liver disease, malignancy, tendency to bleed, and cardioembolic stroke were positively associated with IOS. Compared with COS, IOS was inversely associated with a favorable outcome (42.1% vs 64.8%, adjusted odds ratio [aOR] 0.72 [95% confidence interval (CI) 0.63–0.82]), positively associated with an unfavorable outcome (mRS 5–6 at discharge; 34.3% vs 15.5%, aOR 1.31 [95% CI 1.16–1.48]), and mortality (11.8% vs 4.6%, aOR 1.59 [95% CI 1.37–1.84]). Over 20 years, the mortality rate significantly decreased in both patients with IOS and COS (p < 0.01 both). Conclusion: IOS is associated with unfavorable outcomes and higher mortality rates during acute hospitalization. The mortality rates in patients with IOS decreased over time, similar to those observed in patients with COS.