Cross-sectional case-control studies (Blue)
The impact of COVID-19 on the occurrence of ischaemic stroke has been the subject of increased speculation but has not been confirmed in large observational studies. In this article, the authors investigated the association between COVID-19 and stroke by performing a cross-sectional study involving patients discharged from a healthcare system in New York State, from January to April 2020. A mixed-effects logistic regression analysis and a propensity score–weighted analysis were used to control for confounders and investigate the association of COVID-19 with ischaemic stroke. Similar techniques were used to detect the impact of concurrent COVID-19 infection on unfavourable outcomes for patients with stroke. Among 24 808 discharges, 2513 (10.1%) were diagnosed with COVID-19, and 566 (0.2%) presented with acute ischaemic stroke. Patients diagnosed with COVID-19 were found to have one-quarter the odds of stroke compared with other patients (odds ratio, 0.25 [95% CI, 0.16–0.40]). This association was consistent across all age groups, and results were robust to sensitivity analyses, including propensity score–weighted regression models. In patients presenting with stroke, concurrent infection with SARS-CoV-2 was associated with higher case-fatality (odds ratio,10.50 [95% CI, 3.54–31.18]) and a trend towards increased occurrence of discharge to rehabilitation (odds ratio, 2.45 [95% CI, 0.81–1.25]).
Using a comprehensive cross-section of patients from a large NY-based healthcare system, the authors did not identify a positive association between ischaemic stroke and COVID-19, a conclusion that is different from most other published studies. However, patients with stroke with COVID-19 had worse outcomes compared with those without, with over a 9-fold increase in mortality. The authors underlined that although no definitive conclusions can be reached from this observational study, their data do not support the concerns for an epidemic of stroke in young adults with COVID-19.