COVID uncovered (part 7)
Case severity and NHS staffing levels: a conundrum.
In part 6 of this series I explored a freshly-minted case severity index score (CSI) using freely available bed occupancy data for NHS England. The thinking behind this was very simple: if COVID infection within the population is getting vicious then we’d expect to see mechanical ventilation (MV) beds used in preference to general beds. Number-wise all we do is calculate MV bed occupancy for COVID cases, then calculate general bed occupancy for COVID cases, then derive the ratio of MV bed occupancy to general bed occupancy. This ratio is what I’m calling the case severity index score (CSI) because it should act as a reasonable proxy.
This morning I thought I’d take CSI out for a spin and see what it may or may not explain. I decided to start nice and easy by calibrating the index against something that would make sense: NHS staff absence levels, for instance1. When staff absence due to COVID is high we may reasonably expect the CSI to be running high and so the two series should run tog…