Count rate and prevalence?


New Member
I have a study on surgery in a disease (C)

The prevalence per year is increasing in C over the study period (I have national level data).
To get into the study subjects have an index surgery for C (all the index surgeries are for C so there is no confounding).
This index surgery count is increasing each year, however:

I want to demonstrate that, proportionally, index surgery rates are actually falling given how fast prevalence is increasing (i.e. the denominator for surgery being the number of C subjects in the population.

I have tried dividing surgery count by prevalence of C per year, (kind of weighting the surgery count), but I can't easily explain the resulting value, and certainly can't easily give it a unit?

Any thoughts?

Many thanks