how to calculate prevalence using sql code

Question

I am trying to calculate prevalence in sql. kind of stuck in writing the code. I want to make automative code.

I have check that I have 1453477 of sample size and numbe

Answer 1

I am pretty sure that the logic that you want is something like this:

select avg( (condition_id = 12345)::int )
from disease;

Your version doesn't have the sample size, because you are filtering out people without the condition.

If you have duplicate people in the data, then this is a little more complicated. One method is:

select (count(distinct person_id) filter (where condition_id = 12345)::numeric /
        count(distinct person_id
       )
from disease;