Abstract W P178: Temporal Trends of Emergency Department Arrival Times after Acute Ischemic Stroke: a Population-Based Study

Abstract

Introduction: The largest exclusion criterion for thrombolysis in ischemic stroke (IS) continues to be delayed time of presentation to the ED. We hypothesized that public education regarding IS would lead to improved ED arrival times over two decades within our large biracial population. Methods: We identified all IS patients > 20 years old that presented to an ED by screening ICD-9 codes 430-436 among residents of the Greater Cincinnati/Northern Kentucky Stroke Study region, a biracial population of ~ 1.3 million. Study periods were 7/1/93-6/30/94 and calendar years of 1999, 2005, and 2010. Study nurses abstracted relevant information from the medical record, including symptom onset and ED arrival times, and all potential cases were physician reviewed. Results: There were 1,749 total IS in 1993/94; 1,959 in 1999; 1830 in 2005; and 1912 in 2010. See Figure that displays the distribution of IS patients with known symptom onset time progressively arriving later in each study period. Arrival times stratified by race and gender showed whites arriving later in 2010 than prior study periods (p=0.02). Similarly, males arrived later in more recent periods (p=0.04). Mild IS (NIHSS <5) were less likely to arrive within 3 hrs p <0.001). Additionally, the percentage of mild IS within our population increased over time (55.8% in 1993/94 vs 62.9% in 2010, p<0.0001). After accounting for the increase in mild IS over time, temporal trends in overall arrival times were no longer significant. Discussion: We found that IS patients arrived at progressively later times from 1993/4-2010, and this was driven by an increasing proportion of mild IS patients. It is unknown if this increase in prevalence of mild IS patients is due to improved public awareness of mild stroke symptoms, better detection with MRI, or better management of comorbities. More research is needed to determine the reasons for delayed arrival to medical attention, since time from onset dominates the exclusion of patients from rt-PA.