Thanks very much for picking up this thread.

I’m having some trouble finding the right statistical test for paired ratios (n = 10,000 patients), having not been able to do my usual thing of googling my way to certainty.

I have data in the following layout:

The data are paired e.g. before and after an intervention, and we are looking at the differences in the ratio of canceled appointments : total appointments (in the hope that our intervention reduces cancellations).

Is it correct to use a chi squared test for something like this? I’m trying to do this in R.

Thank you very much for any and all feedback.