As the deadly novel coronavirus continues to spread across the globe, Chinese health officials are revealing new details about the disease’s fatality rate.

A recent study from the Chinese Center for Disease Control and Prevention (CDC) analyzing 72,314 coronavirus cases in mainland China found that while about 80 percent of cases are mild, the virus poses the greatest threat to elderly people with preexisting health issues.

The research shows patients older than the age of 80 had a 14.9 percent chance of dying after being infected, while those in their 70s were found to have an 8 percent chance of death. Patients in their 50s were about three times more likely to die than patients in their 40s, at a rate of 1.3 percent.

Patients ages 10 to 19 were as likely to die as patients in their 30s, at just 0.2 percent. The study did not report any deaths in children younger than 10, who represented less than 1 percent of patients.

The study collected data from confirmed patients through Feb. 11 and is one of the largest such samples in a study of its kind.

The risk of dying dramatically increased among patients in their 70s and 80s as many in this age group are more likely to have preexisting health conditions.

Coronavirus patients with heart disease had a 10 percent mortality rate, while those with diabetes had around a 7 percent mortality rate.

Men were also found to have a 2.8 percent fatality rate, versus 1.7 percent for women, according to the study. The overall fatality rate in China was 2.3 percent.

Scientists say there are a number of factors that could be contributing to why men are more vulnerable in the current epidemic. Some are biological — for example, women have a stronger immune response to viral infections particularly of the respiratory tract — and some are rooted in lifestyle, The New York Times reports. In China, for instance, men smoke in much greater numbers than women.

The World Health Organization (WHO) said Friday people aged 60 and older and have an underlying condition like cardiovascular disease, respiratory condition and diabetes have a risk of developing severe COVID-19. WHO recommended these people avoid crowded areas or places where they might interact with people who are sick.

WHO reported Friday there are more than 82,000 cases worldwide, with more than 2,800 deaths. The majority of cases occurred in China, where the outbreak originated. Health officials said Friday China reported 329 new cases in the past 24 hours, the lowest in over a month.