Hopefully, I can now explain clearer how this problem is occuring...
My query has a list of uniquely named conditions, of which there are tests linked with a one-to many relationship. When I try to use the count([Condition]) function, the report is giving the total number of tests. When I run the query without the report, it is clear that it is showing the condition for each test, meaning that if a condition has more than one test associated with it, it is showing more than once, hence the count being incorrect.
I need a line in the report footer to display how many conditions there are and not how many tests.