Difference between inclusion and exclusion criteria Authors frequently report criteria of selecting subjects in studies in two separate categories, inclusion and exclusion criteria, e.g.:

Inclusion criteria:

age between 18-60

has the disease x


Exclusion criteria:

smoker

has disease y



Alternatively, one can simply put these criteria under one category:

Inclusion (or selection) criteria:

age between 18-60

has disease x

is not smoker

does not have the disease y



Is there a real distinction between the two terms? Or are they used just as a matter of convention?
In some ways the second is clearer since no one will interpret it as the inclusion criteria overriding the exclusion. Your criteria is and for all items. Between 18 - 60 AND ... AND doesn't have disease y. 

But in general, if it is clear what you mean it should be fine. Clarity trumps form.