Abstract 123: Temporal Variation Affect Stroke Unit Admission Rates, Observations From the National Swedish Stroke Register

Abstract

Introduction: It is firmly established that management of acute stroke at dedicated stroke units (SU) improves functioning and survival. Although guidelines recommend SU admission as 1 st level of care for all patients with acute stroke, quality registers show that many patients are treated at non-SU wards. Previous studies have shown that there are different patterns of time that impose an effect on a multitude of outcomes for acute stroke patients. The primary objective of this study was to investigate if there were any temporal variations on direct SU admissions as 1 st destination from the emergency department (ED). Patients and methods: This register study comprised data on patients with acute stroke admitted to any of the 72 Swedish hospitals that register stroke patients in the Swedish stroke register. Patients with transitory ischemic attacks (TIA) were excluded. The study period lasted from January 1, 2011 to December 31, 2015. Unadjusted analyses were followed by logistic regression analyses where we adjusted for the effects of confounding factors (age, sex, consciousness level, hospital, stroke type, thrombolysis, previous stroke, ADL-dependency, diabetes, hypertension and smoking). Results: The study cohort comprised a total of 117 804 patients with acute stroke. In total, 76.0% (89 502 of 117 804) of the patients were directly admitted to a SU from the ED. Unadjusted analyses revealed differences in direct SU admission as a function of time of week; while 83.4% (4033 of 4833) of the patients admitted on Friday mornings were directly admitted to a SU, only 68.4% (483 of 706) of patients admitted Sunday night were directly admitted to a SU. Analyses also revealed a direct admission rate during office hours of 79.9% (41 796 of 52 340) compared to 74.4% (45 812 of 61 605) during off-hours. Finally, monthly variation in direct admission rates ranged from 74.4% (7 803 of 10 483) in January to 77.3% (7 323 of 9 473) in June. Results from the adjusted analyses showed an OR of 2.570 (95% CI 2.132-3.099) for direct admission on Friday morning versus Monday night. Off-hours exhibited an OR of 0.725 (95% CI 0.704-0.747) versus office-hours. June exhibited an OR for direct admission of 1.212 (95% CI 1.127-1.303) compared to January. Discussion: There are several patterns of time affecting admission rates to a SU from the ED. Some of the variation seen in this study could possibly be explained by healthcare organizational factors such as hospital crowding. More studies are however needed to elucidate the mechanisms behind temporal variations as well as the magnitude of these effects on the quality of stroke care. Finally, we believe quality improvement efforts should focus on reducing temporal variation.