Photo/Illutration Kitasato University in Tokyo’s Minato Ward (Asahi Shimbun file photo)

The first study of its kind has revealed how much a COVID-19 patient’s risk of requiring hospitalization or developing serious symptoms increases when four key risk factors are combined.

Those factors are being 65 or older, male, obese, or having type 2 diabetes.

A research team from Kitasato University analyzed the electronic medical records of about 28,000 patients who were infected with the new coronavirus between January and November 2020 in the United States. 

The study analyzed patients that had overlapping risk factors and found the more that patients had, the more likely they needed to be hospitalized.

The rate of COVID-19 patients exhibiting just one of the risk factors who required hospitalization tripled compared to people who had none. The rate of patients with all four risk factors who were hospitalized was about 19 times higher than those with none.

The rate of patients with one risk factor who developed serious symptoms and needed to be treated in intensive care units increased threefold. The rate of patients with two risk factors was 15 times higher, three risk factors was 38 times higher, and all four of the risk factors was a staggering 56 times higher.

The researchers hope their findings will lead to better prediction and prevention of the development of serious symptoms.

The study defined obesity as having a BMI (body-mass index) 30 or higher, using the same standard that the United States adopts.