I believe exists can only be used in a where clause, so you'll have to do a workaround (or a subquery with exists as the where clause). I don't know if that counts as a workaround.
What about this:
create table table1 (col1 int null)
go
select 'no items',CONVERT(bit, (select COUNT(*) from table1) ) -- returns 'no items', 0
go
insert into table1 (col1) values (1)
go
select '1 item',CONVERT(bit, (select COUNT(*) from table1) ) --returns '1 item', 1
go
insert into table1 (col1) values (2)
go
select '2 items',CONVERT(bit, (select COUNT(*) from table1) ) --returns '2 items', 1
go
insert into table1 (col1) values (3)
go
drop table table1
go