Cross-Correlation: Cases, Admissions & Causality

Now that we’ve got the ball rolling using techniques from the world of signal processing I thought we might as well mix metaphors and dive right into the deep end to see whether COVID cases are translating into increased admissions to hospital.

I appreciate this is a tricky stats subject to get your head around so I’ve attached a very useful Wiki link for background. Back in the day time series techniques were taught in the third year for statistics undergrads and 99% of standard text books don’t cover them which is why you won’t see them popping up that often in published papers. Open any clinical paper at random and you’ll see Pearson bivariate correlation, ordinary least squares regression, logistic regression, analysis of variance, multinomial regression and the like despite use of these all resting on the assumption of independence of measure.

The first slide of the morning reveals the cross correlation function for daily new COVID cases with COVID admissions to hospital for Englan…