Patterns and outcomes of weekend admission for acute ischemic stroke

Background and objectives: The “weekend effect” describes worse care delivery during off-hours or weekends and has been demonstrated in multiple sub-specialties. Off-hours care for acute ischemic stroke (AIS) has been associated with poorer outcomes. However, there is less data about the “weekend effect” on endovascular thrombectomy (ET) outcomes. Methods: We used Medicare 100% sample datasets and included all AIS admissions from 2018-2019, using validated International Classification of Diseases, 10th Revision, Clinical Modification codes to identify AIS and comorbidities. Medicare provides the date of admission for all hospitalizations, and the day of the week was determined and assigned to weekend (Saturday or Sunday) or weekday (Monday through Friday). We defined 3 major outcomes: inpatient mortality, discharge home (vs. other destination), and 30-day mortality. Results: Among 471427 AIS admissions,13.0% and 12.9% of all AIS admissions occurred on a Saturday and Sunday, respectively, less than the expected 14.3% occurring on any given day (p-value <0.0001). AIS admissions on a weekend were less likely to receive IV thrombolysis (13.6% on Saturday and 12.9% on Sunday) and ET (13.1% on Saturday and 13.2% on Sunday), p-value <0.0001. Among all AIS admissions, weekend admission was associated with worse outcomes, including higher odds of inpatient mortality (adjusted OR 1.04 [95% CI 1.01-1.08, p<0.0001]), lower odds of discharge home (0.94 [0.93-0.96, p<0.0001]), and higher odds of 30-day mortality (1.06 [1.04-1.08, p<0.0001]). However, among AIS patients treated with ET, there was no association of weekend admission with outcomes. Conclusions: In this national and contemporary dataset, we observed that the proportion of thrombolysis and ET cases was less over the weekend, and outcomes (inpatient mortality, 30-day mortality and odds of discharge home) were worse overall. We did not observe this association among AIS patients undergoing ET on a weekend vs. weekday.