Read an interesting study in JHI with a novel design that I thought I’d share. The study team evaluated the scale of COVID-19 outbreaks across three hospitals in Wales based on characteristics of the ward. When controlling for the things that you think might predict the scale of COVID-19 outbreaks (like speciality, number of toilets, patient age), the thing that came out as the biggest drive of outbreak size was how many patient transfers occurred into the ward. This suggests that the advice from “central command” to minimise patient moves made sense, and still makes sense to reduce the risk of transmissible infectious diseases in our hospitals.