Filters ignored when addition is in a measure

[toddrobertander]

I'm trying to create a measure that calculates the number of patients who have not had a visit within a certain range of time and I came across behavior I don't understand where measures with addition ignore other filters, while other measures (including multiplication) work fine..

Two test measures:

TestAddition = max(patient[patient_id])+1

TestMultiplication = 1*max(patient[patient_id])

The result:

On the left, the filters are ignored for the addition case, while on the right, the filters are applied. 

Why is this happening and is there a common workaorund?

[Anonymous · Accepted solution]

I suspect, without doing any testing cuz I'm lazy, is that you are seeing how Power BI maths up the handling around a BLANK().

BLANK() + 1 = 1

BLANK() * 1 = BLANK()

And rows with blank values get "filtered out"

[toddrobertander]

That makes so much sense. I think it explains everything. I'll have to test it against my more fundamental measure.

Thanks

Todd