Excellent article on Lucy Letby,
@TimboLatto. I think we went on a similar journey but came to different conclusions, perhaps not because of a total difference in methodology but because of our base assumptions.
I have the annual base rate of deaths at the hospital at 2.4, rather than 4. I also have Letby on duty for 12/13 deteriorations that led to death at the Countess, which I believe is the relevant stat. Two babies went into resus shortly before her shift ended but were declared dead just after. For consistency, if a baby had gone into resus before her shift but died during it, I wouldn’t count that as occurring on her shift — but that wasn’t the case for any infant.
I also have her on duty for 21.4% of the time, rather than 25%: the police-compiled rota shows her working 163 12.5-hour shifts between June 2015 and June 2016.