National trends in outcomes of ischemic stroke and prognostic influence of stroke center capability in Japan, 2010–2016

Background: Limited national-level information on temporal trends in comprehensive stroke center capabilities and their effects on acute ischemic stroke patients exists. Aims: To examine trends in in-hospital outcomes of acute ischemic stroke patients and the prognostic influence of temporal changes in comprehensive stroke center capabilities in Japan. Methods: This retrospective study used the J-ASPECT Diagnosis Procedure Combination database and identified 372,978 acute ischemic stroke patients hospitalized in 650 institutions between 2010 and 2016. Temporal trends in patient outcomes and recombinant tissue plasminogen activator (rt-PA) and mechanical thrombectomy usage were examined. Facility comprehensive stroke center capabilities were assessed using a validated scoring system (comprehensive stroke center score: 1–25 points) in 2010 and 2014. The prognostic influence of temporal comprehensive stroke center score changes on in-hospital mortality 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. The median comprehensive stroke center score increased from 16 to 17 points. After adjusting for age, sex, comorbidities, consciousness level, and facility comprehensive stroke center score, proportion of in-hospital mortality and poor outcomes at discharge decreased (from 7.6% to 5.0%, and from 48.7% to 43.1%, respectively). The preceding comprehensive stroke center score increase (in 2010–2014) was independently associated with reduced in-hospital mortality and poor outcomes, and increased rt-PA and mechanical thrombectomy use (odds ratio (95% confidence interval): 0.97 (0.95–0.99), 0.97 (0.95–0.998), 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 mechanical thrombectomy in acute ischemic stroke. In addition to lesser stroke severity, preceding improvement of comprehensive stroke center capabilities was an independent factor associated with such trends, suggesting importance of comprehensive stroke center capabilities as a prognostic indicator of acute stroke care.