Japan's top modeller

The top three greatest misses of Hiroshi Nishiura, the Japanese Neil Ferguson

Meet Hiroshi Nishiura, professor of theoretical epidemiology at Kyoto University and the Japanese government’s go-to guy for pandemic projections. Since the Winter Olympics has just been held, we’ll hand out medals to his top three predictions.

1. The bronze medal goes to his predictions for reported cases in Tokyo in early 2021. The government took the red-line option of telling bars and restaurants to close at 20:00…

[https://www.asahi.com/ajw/articles/14088536']

…which amazingly caused the reported cases to peak the very next day!

[https://www.bloomberg.com/news/articles/2021-04-22/tokyo-seeks-new-state-of-emergency-as-virus-cases-rise]

1. The silver medal goes to his prediction of potentially over 100,000 cases (red line) in Tokyo by the end of August 2021 if the government took no further action to limit people’s contacts, which they didn’t. His projection for the most likely outcome (blue line) was “only” 32,280 cases by August 26th….

[https://news.yahoo.co.jp/byline/yanaihitofumi/20210913-00257956]

…which was only about 6.5 times higher than the actual number.

[https://toyokeizai.net/sp/visual/tko/covid19/en.html]

1. However, the winner of the gold medal was never in any doubt: Nishiura’s April 2020 projection of 850,000 patients needing mechanical ventilation, of whom 49% (420,000) would die if people carried on as normal during the first wave.

   

   [https://www.ntv.co.jp/news_covid19/static/20200415_08.html]

So how many Covid patients have actually needed mechanical ventilation?

[https://crisis.ecmonet.jp/]

At this rate, the 850,000th Covid patient to require mechanical ventilation should be admitted to hospital in the year 2220.

One projection that failed to win a medal was Prof Nishiura’s prediction of up to 10,000 serious cases in Tokyo if the Olympics were held with spectators.

[https://news.yahoo.co.jp/articles/146428600d7967a2afd79e7be372580b85374aa1]

Thankfully, the Olympics were held without spectators based on this projection, so Tokyo’s serious cases peaked at under 300. However, we’ll never know how close Prof Nishiura’s projection of 10,000 would have come to being realized…

…which is probably why he looks so happy.