Global Impact of the COVID 19 Pandemic on Stroke Care, Cerebral Venous Thrombosis, and Subarachnoid Hemorrhage

Overview

A 1-year analysis of global selected stroke metric data will be conducted comparing the results during the Covid-19 pandemic to the pre-pandemic period. In most countries, this will correspond to March 1, 2020 to February 28, 2021. In some countries, the pandemic period would be adjusted for onset of case surge (i.e. China pandemic start date would begin earlier, i.e. January 2020). The specific metrics that will be analyzed include: 1. ischemic stroke or transient ischemic attacks (TIA) hospitalizations 2. intracranial hemorrhage hospitalizations 3. cerebral venous thrombosis (CVT) hospitalizations (with or without thrombocytopenia) 4. CVT in-hospital mortality 4\) aneurysmal subarachnoid hemorrhage hospitalizations 5) mechanical thrombectomy 6) intravenous thrombolysis 7) ruptured aneurysm endovascular coiling 8) ruptured aneurysm clipping. 9) aneurysmal subarachnoid hemorrhage admissions 10) SAH in-hospital mortality 11) SAH presentation by Hunt Hess Grade

This is a retrospective, observational, cross-sectional, international study, across 6 continents, and estimated 100 stroke centers. The stroke metric diagnoses will be identified by their International Classification of Diseases version 10 (ICD-10) codes and/or classifications in stroke databases at participating centers. Aggregate monthly volume will be obtained from January 1, 2019 to May 31, 2021. For CVT related to COVID vaccine events, the study period extends until July 30, 2021 The primary hypotheses to be tested are: * The overall 1-year volumes of the stroke metrics will be decreased compared to the prior year. * With each subsequent COVID wave, there will be a decline in relation to the prior year volumes, as was seen with the first COVID-19 wave of the pandemic. * A recovery or increase in stroke volume will occur during the vaccine roll-out phase on same metrics, compared to the immediately preceding period and/or compared to the same period one year prior. * There will be a decline in mild clinical severity in the presentation of patients with subarachnoid hemorrhage as measured by the Hunt Hess Grade scale, parallel to the decline in mild severity of stroke admissions seen with the first wave of the pandemic. \[Mild severity of presentation is defined as Hunt Hess Grade 0-2, moderate to severe is defined as Hunt Hess Grade 3-5.\] * There will be an increase of CVT diagnosis during the COVID-19 pandemic year, related either to heightened awareness of COVID-19 and thrombotic events, or related to reported associations of CVT and COVID-19. The ICD codes utilized for the diagnosis are as follows: Ischemic Stroke, ICD-10 Codes I63.0 Cerebral Infarction I63.1 Cerebral infarction due to embolism of precerebral arteries I63.2 Cerebral infarction due to unspecified occlusion or stenosis of precerebral arteries I63.3 Cerebral infarction due to thrombosis of cerebral arteries I63.4 Cerebral infarction due to embolism of cerebral arteries I63.5 Cerebral infarction due to unspecified occlusion or stenosis of cerebral arteries I63.8 Other cerebral infarction I63.9 Cerebral infarction, unspecified Intracranial Hemorrhage, ICD-10 Codes I61 Nontraumatic intracerebral hemorrhage I61.0 Nontraumatic intracerebral hemorrhage in hemisphere, subcortical I61.1 Nontraumatic intracerebral hemorrhage in hemisphere, cortical I61.2 Nontraumatic intracerebral hemorrhage in hemisphere, unspecified I61.3 Nontraumatic intracerebral hemorrhage in brain stem I61.4 Nontraumatic intracerebral hemorrhage in cerebellum I61.5 Nontraumatic intracerebral hemorrhage, intraventricular I61.6 Nontraumatic intracerebral hemorrhage, multiple localized I61.8 Other nontraumatic intracerebral hemorrhage I61.9 Nontraumatic intracerebral hemorrhage, unspecified Cerebral Venous thrombosis, Codes G08 Intracranial Phlebitis and Thrombophlebitis I63.6 Cerebral infarction due to cerebral venous thrombosis, nonpyrogenic I67.6 Nonpyrogenic Thrombosis of Intracranial Venous System O22.5 Cerebral venous thrombosis in pregnancy Subarachnoid Hemorrhage, Codes I60.0 Nontraumatic subarachnoid hemorrhage from carotid siphon and bifurcation I60.1 Nontraumatic subarachnoid hemorrhage from middle cerebral artery I60.2 Nontraumatic subarachnoid hemorrhage from anterior communicating artery I60.3 Nontraumatic subarachnoid hemorrhage from posterior communicating artery I60.4 Nontraumatic subarachnoid hemorrhage from basilar artery I60.5 Nontraumatic subarachnoid hemorrhage from vertebral artery I60.6 Nontraumatic subarachnoid hemorrhage from other intracranial arteries I60.7 Nontraumatic subarachnoid hemorrhage from unspecified intracranial artery I60.8 Other nontraumatic subarachnoid hemorrhage I60.9 Nontraumatic subarachnoid hemorrhage, unspecified COVID19 UO7.1