Abstract WP350: National Trends in Outcomes of Ischemic Stroke and Prognostic Influence of Stroke Center Capability in Japan

Abstract

Background: Limited national-level information on temporal trends in comprehensive stroke center (CSC) capabilities and their effects on acute ischemic stroke (AIS) patients exists. Aims: To examine trends in in-hospital outcomes of AIS patients and the prognostic influence of temporal changes in CSC capabilities in Japan. Methods: This retrospective study used the J-ASPECT Diagnosis Procedure Combination database and identified 372,978 AIS patients hospitalized in 650 institutions between 2010 and 2016. Temporal trends in patient outcomes and recombinant tissue plasminogen activator (rt-PA) and mechanical thrombectomy (MT) usage were examined. Facility CSC capabilities were assessed using a validated scoring system (CSC score: 1-25 points) in 2010 and 2014. The prognostic influence of temporal CSC score changes on in-hospitalmortality and poor outcomes (modified Rankin Scale: 3-6) at discharge were examined using hierarchical logistic regression models. Results: Over time, stroke severity at admission decreased, whereas median age, sex ratio, and comorbidities remained stable. During the study period, usage of rt-PA and MT in rural areas remained lower than that of urban areas, but in 2016, the differences in their use were within 1%. The median CSC score increased from 16 to 17 points. After adjusting for age, sex, comorbidities, consciousness level, and facility CSC score, proportion of in-hospitalmortality and poor outcomes at discharge decreased (from 7.6% to 5.0%, and from 48.7% to 43.1%, respectively). The preceding CSC score increase (in 2010-2014) was independently associated with reduced in-hospital mortality and poor outcomes, and increased rt-PA and MT use (odds ratio (95% confidence interval): 0.97(0.95-0.99), 0.97(0.95-1.00), 1.07(1.04-1.10), and 1.21(1.14-1.28) , respectively). Conclusions: This nationwide study revealed six-year trends in better patient outcomes and increased use of rt-PA and MT in AIS. In addition to lesser stroke severity, preceding improvement of CSC capabilities was an independent factor associated with such trends, suggesting importance of CSC capabilities as a prognostic indicator of acute stroke care.