Abstract 46: Cumulative Incidence of Stroke Disability/mortality Following Emergency Department Discharge for Dizziness

Introduction: Providers are often concerned about missing stroke in Emergency Department (ED) dizziness visits. Prior studies found that the cumulative incidence of stroke after ED discharge for dizziness is low. However, little is known about the magnitude of disability and/or severity of subsequent strokes which is important for informing the scope of the problem. We aimed to estimate the cumulative incidence of stroke-disability/mortality following ED dizziness visits that were discharged home. Methods: We conducted a retrospective cohort study from January 2016 to December 2020 across 13 EDs within Kaiser Permanente Southern California (KPSC). We included all index visits for adults who were discharged home from the ED after a primary dizziness visit, excluding those with DNR/hospice status, trauma, or index stroke diagnosis. Post-stroke disability/mortality - defined as stroke hospitalization not discharged home - was captured over a 30-day follow-up period. Cumulative incidence of stroke-disability/mortality was calculated using Kaplan-Meier estimates censored for non-stroke death. Acute stroke management was also summarized. Results: We identified 77,315 index dizziness visits discharged home from the ED. Median age was 59 years (IQR,44-71) and 62% were female. The 30-day cumulative incidence of stroke-hospitalization was 0.12% (95% CI 0.10-0.15%; 1 in 823) and the cumulative incidence of post stroke-disability/mortality was 0.04% (95%CI 0.03-0.06; 1 in 2,342). At the subsequent stroke-hospitalizations, the frequency of acute interventions was as follows: 3% (3/94) intra-arterial thrombolytics, 5% (5/94) thrombectomy, 2% (2/94) suboccipital craniotomy, 3% (3/94) tracheostomy, 3% (3/94) gastrostomy, 10% (9/94) mechanical intubation. Conclusions: The cumulative incidence of post stroke-disability/mortality among patients discharged from the ED for dizziness is low and acute interventions used to manage severe strokes were infrequent. These data are important for planning studies to optimize outcomes of patients presenting to the ED for dizziness.