Abstract 71: Temporal Trends In 30-day And 5-year Stroke Case Fatality Rates

Background: Previous studies spanning the 1990s-2010s have inconsistently identified a decline in 30-day stroke case-fatality rate (CFR), and little is known about trends in longer term stroke CFR over that period. We studied temporal trends in 30-day and 5-year CFRs in the well-defined Greater Cincinnati/Norther Kentucky (GCNK) stroke population. Methods: The NIH-funded GCNK Stroke Study is a population-based study conducted in a 5-county region that is representative of the USA in terms of Black race, income, and education. The study ascertained all strokes in 1993/4, 1999, 2005, 2010, and 2015 using well-validated methods. All stroke subtypes were included: ischemic strokes (IS), intracerebral hemorrhages (ICH), and subarachnoid hemorrhages (SAHs). Deaths were identified via the National Death Index. Cox proportional hazards models were used to assess all-cause fatality, by subtype, to examine temporal trends adjusting for age, sex, and race. Results: A total of 10372 stroke cases were ascertained over the five study periods (8428 IS, 443 SAH, and 1501 ICH). IS patients did not demonstrate a decline in 30-day CFRs over time, but did show a nonsignificant decrease in 5-year CFR. Among IS patients, female sex was associated with a lower 5-year CFR, whereas Black individuals had a lower 30-day CFR but a higher 5-year CFR. For ICH, there was a small increase in both 30-day and 5-year CFR in later study periods, although this did not reach significance in all years. SAH showed a lower 30-day CFR over time but no change in 5-year CFR. Older age was associated with a higher 30-day and 5-year CFR in all subtypes. Discussion: Despite widespread advances in post-stroke care, adjusted 5-year CFR has not clearly improved for any stroke subtype and may have slightly worsened for ICH. 30-day CFR has shown a modest improvement among SAH patients. Future studies should investigate why Black individuals with IS experience lower early CFR but a higher late CFR.