The Case Fatality Rate is the ratio of deaths from a certain disease to the total number of people diagnosed with this disease. But it is misleading [2009, T. Garske, J. Legrand] at the beginning of a pandemic. Deaths can have various causes and the number of people diagnosed depends on how many tests are performed and how we chose who to test.
As long as hospitals are able to accommodate patients, no. of hospitalized people are the most reliable data. Every person with a severe shortness of breath or with difficulties in breathing is hospitalized and tested for the COVID-19 infection.
In addition to providing a realistic picture of the rate of spread of the disease, this number also indicates how close we are to the catastrophe of the health system.
Below is a graph of the no. of people hospitalized in Italy since February 24 for COVID-19.
An Intensive Care Unit, is a special department of a hospital or health care facility that provides intensive treatment medicine for patients with a very severe disease.