Multivalue Parameters For Filter Not Working

Hi,

I've tried using the same method mentioned in the dozens of posts dedicated to this topic but it's not working.

My SQL statement is:

SELECT [University Origins].Origin, COUNT([University Origins].Origin) AS TotalCount, Hospitals.Name
FROM Posts INNER JOIN
Hospitals ON Posts.HospitalID = Hospitals.[Hospital ID] CROSS JOIN
[University Origins] INNER JOIN
Incumbents ON [University Origins].[Uni Origin ID] = Incumbents.[University Origin]
WHERE (NOT ([University Origins].Origin = 'No answer')) AND (Hospitals.Name IN (@HospitalFilter))
GROUP BY [University Origins].Origin, Hospitals.Name


The HospitalFilter parameter is set to Multivalue and it's populated with it's own SQL statement giving the Distinct Hospitals.

I have setup a filter on my table with the following expressions:

Expression: =Trim(Fields!Name.Value)
Operator: = IN
Value: =Trim(Parameters!HospitalFilter.Value.ToString )

I have used Trim to remove leading and trailing spaces.

Running the report always returns zero results and I'm puzzled by this. Would appreciate any advice and suggestions

Thanks,
John