ABSTRACT
Background: Studies have shown that patients with ischemic stroke (IS) and concurrent COVID-19 have increased stroke severity. These analyses were limited by use of prepandemic era controls or by utilization of a sample from the early pandemic period when stroke care delivery was affected by lockdown. Studies on the severity of hemorrhagic stroke (HS) in patients with concurrent COVID-19 are few and limited by small sample sizes. Methods: Using the National Institute of Health (NIH) National COVID Cohort Collaborative (N3C) database, we identified patients diagnosed with stroke between Mar 1, 2020 - Feb 28, 2021. Hospitalized stroke patients with concurrent COVID-19 (stroke within 3 months after or one week prior to positive SARS-COV-2 PCR or AG lab test) were matched to all other hospitalized stroke patients in a 1:3 ratio. Nearest neighbor matching with a caliper of 0.25 was used for most clinical and demographic factors;exact matching for race/ethnicity and site. Within our matched sample, we used Poisson regression to calculate stroke severity incident rate ratio (IRR). Results: Our query identified 10,394 patients hospitalized with IS with available NIHSS scores upon admission (802 with concurrent COVID-19 and 9,592 without) and 2138 patients hospitalized with HS (181 with concurrent COVID-19 and 1957 without). Average NIHSS was greater in concurrent groups with both IS and HS (11.1 vs 7.68, p < 0.001 and 15.7 vs 11.7, p < 0.001 respectively). Propensity matched analysis also demonstrated that stroke patients with concurrent COVID-19 had increased initial NIHSS (IS: IRR = 1.4, 95% CI:1.3-1.5, p-value < 0.001;HS: IRR = 1.3, 95% CI:1.2- 1.5, p < 0.001). Average NIHSS in both IS and HS patients was greater in the Mar-Apr 2020 epoch than in all other 2 month epochs studied in these respective groups. Conclusions: This analysis suggests that the association between increased stroke severity and concurrent COVID-19 that was observed during the early pandemic was present throughout the pandemic as stroke care utilization normalized. Further work will center on the interaction between COVID-19 illness severity and stroke severity.