Coronavirus Disease 2019 (COVID -19) is the largest public health crisis in over a century. There is an urgent need for high-quality population-level data to understand modifiable risks for disease severity, transmissibility, and to develop evidence-based prevention (i.e. vaccination), treatment and resource allocation strategies.

The Canadian COVID-19 Emergency Department Rapid Response Network (CCEDRRN) created a population-based registry of suspected and confirmed consecutive cases of COVID-19. The purpose of this registry is to derive and validate clinical decision rules, evaluate diagnostic tests and vaccine effectiveness, and complete cohort, case-control and observational studies to inform the pandemic response.

This national multi-centre registry is designed to enroll population-based consecutive eligible patients presenting with suspected or confirmed COVID-19 to 50 emergency departments in eight Canadian provinces from March 1 2020 and data collection is ongoing for the duration of the pandemic.

Data will be abstracted from the medical chart and entered into a central, web-based REDCap database. The investigators adopted the ISARIC variables into the database where there was a match. The investigators will develop standardized operating procedures for screening of potentially eligible patients, data entry and follow-up. Current data dictionaries are kept on the registry's website (https://canadiancovid19registry.org/).

At 30 days, the investigators will contact patients by telephone to obtain verbal consent for follow-up. The investigators will measure the Veterans Rand 12-item Health Survey (VR12), calculate the WHO Ordinal Outcome Scale and ask contextual questions in consenting patients. The VR12 will be measured at 60 days, and 6 and 12 months. The contextual questions were developed with input from patients with lived experience with COVID-19 infection and addressed cultural, racial, gender, socioeconomic and self-isolation issues.

The Health Data Research Network facilitated the development of a unique data flow of personal health identifiers and study identification numbers from each province for all participating institutes. This will allow linkage of registry data with national administrative data repositories.

The investigators defined two periods for enrollment based on the availability of COVID-19 testing. Research assistants used medical microbiology testing and discharge diagnoses to screen for potentially eligible patients.

In Period 1, COVID-19 testing in each province was restricted to specific patient populations (e.g., healthcare workers, admitted patients).

Inclusion Criteria:

• Meeting the WHO suspect COVID-19 criteria: Fever (self-reported or subjective fever) and at least one symptom/sign of respiratory illness (e.g., flu-like illness, cough, shortness of breath)
• Presenting to the emergency department and tested for COVID-19 in the emergency department

No exclusion criteria in Period 1

Period 2 started on the date which each province expanded testing criteria allowing clinicians to test patients based on clinical suspicion or policy.

Inclusion Criteria:

• Presenting to the emergency department within 14 days of a positive COVID-19 (by self-report or in medical chart) and presents with clinical symptoms consistent with COVID-19
• Tested for COVID-19 in the emergency department, or within 24 hours after emergency department arrival.

Exclusion Criteria

• Patients tested for COVID-19 in the context of an elective admission (e.g., planned hip revision)
• Patients tested for COVID-19 and seen in the emergency department directly by another service (e.g., trauma team activation)

Patients presenting to participating Canadian emergency departments with suspected and or confirmed COVID-19.