==== Front Innov Aging Innov Aging innovateage Innovation in Aging 2399-5300 Oxford University Press US 10.1093/geroni/igaa057.3250 igaa057.3250 Abstracts Session 10120 (Late Breaking Poster) Alzheimer’s Disease and Related Dementias AcademicSubjects/SOC02600 Pre-stroke dementia and in-hospital outcomes in the Chinese Stroke Center Alliance Liu Chelsea 1 Gu Hong-Qiu 2 Yang Xin 2 Wang Chun-Juan 2 Yang Kai-Xuan 2 Li Zi-Xiao 2 Wang Yong-Jun 2 1 Harvard School of Public Health, Boston, Massachusetts, United States 2 Beijing Tiantan Hospital, Beijing, China 2020 16 12 2020 16 12 2020 4 Suppl 1 Program Abstracts from The GSA 2020 Annual Scientific Meeting “Turning 75: Why Age Matters”880 880 © The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America.2020This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Abstract Little is known about the prevalence of pre-stroke dementia in China and whether this group is at higher risk of adverse in-hospital outcomes. We aimed to understand this association using data from the Chinese Stroke Center Alliance. Multivariable logistic regressions were conducted to assess the association between pre-stroke dementia status and ambulation at day 2, in-hospital mortality, and in-hospital complications. Covariates included age, sex, medical history, history of smoking, history of alcohol use, medication history (antiplatelet drugs, lipid-lowering drugs), stroke severity (measured by the National Institute of Health Stroke Scale), whether IV tPA was administered within 4.5 hours, and whether the patient received deep vein thrombosis prophylaxis as needed. Odds ratios and 95% confidence intervals were presented for the adjusted models. In the final analytic sample of 559,070 ischemic stroke patients with no prior stroke history enrolled across 1476 hospitals, 1511 (0.3%) had pre-stroke dementia, and they were older and more likely to be female. Patients with pre-stroke dementia had lower odds of ambulating at day 2, higher odds of having any complications and higher odds of in-hospital mortality compared to those without pre-stroke dementia, despite little difference in treatment received. Our findings may be explained by communication barriers experienced by patients with pre-stroke dementia that limited their ability to advocate for their own care needs. Further research is needed to determine whether a different care pathway or additional attention from clinicians is necessary for patients with pre-stroke dementia.