This was the article.
https://www.wired.com/story/could-chinas-new-coronavirus-become-a-global-epidemic/
Calculation quotes from
https://maimunamajumder.com/
"
So far, Chinese health authorities have followed 1,070 people who’ve come into contact with infected patients in Wuhan, cleared 739 of them, and are still monitoring 331, according to
official reports. They have yet to share information about individual cases with the rest of the world—essential details such as what their age and sex are, when they started developing symptoms, what they might have been exposed to, and what condition they’re currently in. That information could be vital to assessing the mortality risk factors associated with 2019-nCoV, says Maia Majumder, a public health researcher at the Computational Health Informatics Program based out of Harvard Medical School and Boston Children’s Hospital. “Then we could analyze what makes people who die from the infection different from the ones that recover.”
Lacking this data, researchers can only make vague estimates of the virus’s fatality. The math is pretty simple: Divide the number of deaths by the number of people known to have died or survived. It can be tempting to include hospitalized individuals, but because their outcomes are unknown, they can provide a false sense of security. In mainland China, nine out of 471 infected people have died. Doesn’t seem so bad. But if you exclude the hundreds of patients who are still hospitalized—who may yet die or survive—now you have a death rate approaching 20 percent. Is that closer to the real death rate? Hard to say. The point is, it’s all just guesses if you only have case numbers at this point in an outbreak."
its also from the 22nd so quite out of date now and appears to have been edited in places.