Going Coronaviral: New York City Will Be Shut Down By the End of Next Week

Note: To read an updated and improved version of this post, please click here. It has more accurate numbers and clearer explanations, and I recommend you read it instead.

If that title seemed half funny, this post, unfortunately, will not. Panicking never helps, so please don’t panic, but by the end of next week, New York City will likely be shut down. Here’s why, in four graphs.

Sadly, it gets worse. Accordingly to the following graph from a study by the Journal of the American Medical Association (JAMA) of ~45,000 cases of COVID-19 in Wuhan, the number of confirmed cases (here: “By date of diagnosis”) lags but roughly mirrors the number of actual cases (here: “By date of onset”) by roughly a week.

Put simply, the trends or the curves look more or less the same (if anything, the number of actual cases climbs more steeply until the drastic preventive measures – in this case, the “shut down” of Wuhan, a city with a population greater than that of the five boroughs – take effect), so we can approximate the number of actual cases by simply extrapolating the predicted number of confirmed cases a week ahead. There’s no saying that the pattern in New York is exactly analogous to that in Wuhan, but, in both cases, municipal, provincial/state, and national governments were caught totally unprepared by a novel pathogen, and – in spite of having had two-plus months lead time and the advantage of their example – I wouldn’t say we’ve done any better in handling this here than our peers in Wuhan did there.

That said, let’s apply this same approach to the New York numbers. This gets very ugly. (See correction below! Owing to a math error I made, this turns out to be at once an underestimation of the worst-case scenario, and an overestimation of the likely outcome. The corrected estimates are still terrifying.)

I’ve made multiple assumptions here (about the trend of confirmed cases going forward and the relationship between confirmed cases and total actual cases, most saliently), but all founded on the best available data of which I’m aware. If these numbers are anywhere near correct, then we could be looking at ~100,000 actual cases of COVID-19 in New York City by next weekend. New York City has ~20,000 total hospital beds and 5,000 ventilators. Given that ~20% of COVID-19 patients require hospitalization, and approximate 5% of patients require intensive care, we could be at or beyond the capacity of the City’s medical system by this time next week. This is why the idea of flattening the curve became ubiquitous in recent days; unfortunately, we’ve likely missed the opportunity to flatten it enough to avoid a real crisis, but what we do in the coming days will determine how bad that crisis gets. Every day we delay, this gets worse.

If it’s helpful, and for people to prove me wrong in case I am, below are the NYC data and predicted values upon which the graphs are based.

Postscript: Correction. I caught my own error before someone else could. I conflated rate of change in the JAMA graph with the trend itself. Just ran the numbers again (leaving the erroneous spreadsheet – only the “Estimated Cases” are incorrect – above from the original post, and will try to share corrected spreadsheet in the morning). For better estimates and clearer explanations, please read this post instead.