The methodology seems to be described in the linked research paper, which should be the article linked, not this lame summary: https://www.bmj.com/content/363/b

The methodology seems to be described in the linked research paper, which should be the article linked, not this lame summary: https://www.bmj.com/content/363/bmj.k4583 https://www.bmj.com/content/363/bmj.k4583