Media sources worldwide have been flooded with articles about the new coronavirus. Suggestions on social-distancing, working from home, maintaining good mental health and using online technologies have overwhelmed every application and email I open on my phone.

No matter what the source, the message has always been to stay home — if not for yourself, for your grandparents, for your immuno-compromised friends and for your peers with pre-existing conditions. As an epidemiologist-in-training with a lot more time on her hands than before, I wanted to understand the risk of COVID-19 for those who already have other conditions. I decided to do some digging. Although I do not have access to all the data — much of it is still being collected — one thing is clear: everyone should stay home as much as possible, not just for themselves, but more so for those with pre-existing conditions.

People have been saying this quite a lot since the start of the pandemic. But they often do so repeating what they have heard on news outlets or TV without understanding the details of why this is so important.

There are several fancy dashboards, such as the WHO Situation Dashboard and the Johns Hopkins Center for Systems Science and Engineering Dashboard, that update in real time the total number of COVID-19 cases and deaths in each country. However, there is little to no publicly available information on COVID-19 patient characteristics, such as presence of pre-existing conditions that may have put them at a higher risk of catching the virus.

Seeing this gap in knowledge, I have been specifically interested in understanding — out of all the patients that were diagnosed with COVID-19 — how many had pre-existing conditions? I was also looking to get a breakdown by type of condition, such as asthma, cardiovascular diseases, cancer and immune disorders. After several days of literature review and asking professors and public health librarians, I finally had some information to work with. I hope this makes clear to you why staying at home is the most important thing you can do.

It is clear that those with serious medical conditions are at a higher risk for severe illness due to COVID-19. An article in the peer-reviewed medical journal Lancet looked at 99 patients at a Wuhan hospital over three weeks in January and found that out of all the patients, 40 percent had cardiovascular and cerebrovascular diseases. Moreover, 13 percent had endocrine system diseases, 11 percent had digestive system diseases and one percent had malignant tumors. That means that 65 percent of patients included in the study had at least one chronic condition.

It should thus come as no surprise that the CDC recommends that people maintain a six-foot distance between each other, and the NHS suggests that people who belong to the high-risk group should be at least six-and-a-half feet away from others, including people in their own homes. Since COVID-19 spreads from person to person through respiratory droplets and infected surfaces, it is upon each and every one of us to prioritize our communities and the people most at risk over the inconvenience of staying indoors.

But in spite all of this, it is wrong to make rash generalizations across different countries, and we must be careful not to make broad claims that aren’t backed by evidence. Italy’s COVID-19 Surveillance Group reported that as of March 24th, out of 514 patients who died due to COVID-19, more than 20 percent had heart complications and about 17 percent had an active cancer in the last five years. The data reveals major differences from that collected in the Wuhan study. Therefore, we should not use what happens in one country to conclude that other countries will follow an identical path.

And yet, there are larger trends at play: COVID-19 hits those with pre-existing conditions the worst. So next time you’re thinking of attending that house party, wait for your government’s green light. You may just save someone’s life.

RIA RUNGTA is an MPH candidate in chronic disease epidemiology at the Yale School of Public Health. Contact her at ria.rungta@yale.edu .