Facts Behind the Numbers of COVID-19 Cases

A single figure doesn’t tell much. The relationship between two numbers is more interesting, especially between one and the total number of confirmed cases.

*The proportion of patients who have recovered: the higher, the better.

A high rate of recovery is usually due to a great proportion of the patients with mild diseases, because it takes much longer time for patients with severe symptoms to recover than those with mild or no symptoms.

Active measures, such as conducting massive PCR testing and efficient contact tracing, are needed to find out more people with Covid-19.

*The proportion of hospitalized patients: the lower, the better.

A high rate of hospitalization reveals there are a large number of unconfirmed patients. It is usually caused by inadequate test capacity, as testing has been prioritized for severe cases.

A normal rate of hospitalized patients is about 3.4% if all the cases have been discovered. The higher the rate, the more unconfirmed patients are spreading the virus unintentionally.

*The proportion of patients who have died (also known as CFR): the lower, the better.

A high CFR is often observed at the hospitals overwhelmed by patients, because doctors have to prioritize scarce resources like ventilators for some patients while leaving others on their own.

To relieve pressure on hospitals, it is necessary for people to practice physical distancing, mask wearing, hand cleaning and etc. Effective vaccines and drugs will be the best ways to save lives. So far, dexamethasone, a worldwide drug with affordable price, has been found to reduce the mortality rate by 20% among critically ill patients [1].


1. Coronavirus breakthrough: dexamethasone is first drug shown to save lives. NATURE 16 June 2020.

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