COVID-19 pandemic has developed worldwide in less than 4 months. The clinical presentations are variable widely, ranging from simple rhinitis to major lung damage that can lead to death.

In many countries involved in the ongoing health disaster due to SARS-CoV-2 infection, hospital are overloaded. In this context, the decision to hospitalize or to manage COVID-19 patients at home is crucial and defining reliable and consensual criteria is a major issue.

HOME-CoV study is a multicentre quasi-experimental interventional study, before and after implementation of a help-decision making rule (HOME-CoV rule), developed via the Delphi method.

Our main hypothesis is that a strategy based on the consensual HOME-CoV rule compared to current practice is at least as safe as regards the 7-day-rate of adverse events (safety criterion) and more effective as regards the rate of patients eventually managed as outpatients (efficacy criterion).

Definition of HOME-CoV rule:

The Delphi method is used to reach a consensus of a large panel of experts and to define an easy-to-use clinical rule aiming to help emergency physicians in hospitalisation or outpatient management decision making : the HOME-CoV rule.

The impact of the rule implementation is evaluated in a before and after study:

• before period: observational assessment of current practices
• implementation period : educational lectures, posters, and pocket cards showing and explaining HOME-CoV rule are communicated to participating Emergency Departments.
• after period : observational assessment of practices

In each period, patients consulting Emergency Departments with suspected or probable COVID-19 are evaluated for potential inclusion. Clinical, biological and imaging data that may be involved in decision-making about hospitalization are collected as well as the physician final decision (hospitalization or outpatient management) and its main determinants.

A phone-call follow-up is performed and the clinical status according to the Ordinal Scale for Clinical Improvement of COVID-19 from the World Heath Organization is collected on day 7 and day 28 following inclusion.

Inclusion Criteria:

• Adult patient (≥ 18 years old)
• Admitted for COVID-19 infection confirmed by a positive SARS-CoV2 RT-PCR or considered probable by the physician in charge of the patient.
• Not requiring care in intensive care unit or resuscitation unit or
• No subject of a limitation decision of active therapies,
• Free informed express consent to participate in the study orally given or signed by the patient according to local legislation,
• Insurance cover according to local legislation;

Exclusion Criteria:

• Patient whose main diagnostic hypothesis in the emergency room is not a SARS-CoV-2 infection but another differential diagnosis,
• Patient admitted to the emergency room for 18 hours or more,
• Patient whose follow-up on D28 is impossible, whatever the reason,
• Patient with a poor understanding of the French language,
• Patient already included in the study,
• Person deprived of their liberty by judicial or administrative decision,
• Person under psychiatric care under duress,
• Person subject to a legal protection measure,
• Person unable to express consent.