SubQuery In Both SELECT And WHERE Part. How To Optimise?

Ok I have the following SQL, I have a subquery in the SELECT part but also the same subquery in the WHERE part as well.

What I'm trying to do is get all parents that have children OR get all parents with no children OR just get all parents regardless (@HasResponses is a BIT that can be 1, 0 or null). At the same time I want to count the total number of children in the select list, but I'm having to copy the same subquery in the SELECT and WHERE parts which doesn't seem terribly optimal to me (maybe it is, that's why I'm asking). I've tried referencing the column alias in the select list (AS [Responses]) for the where part (@HasResponses = 0 AND [Responses] = 0), but it doesn't seem to work.

Is this the most optimal way to do it? Is there a better way? I'm working with SQL Server 2005.

SELECT
f.FeedbackText AS [Feedback Comment],
u.Name AS [Feedback Author],
f.CreatedDate AS [Created On],
(
SELECT COUNT(*)
FROM FeedbackResponse fr
WHERE fr.FeedbackID = f.ID
) AS [Responses]
FROM Feedback f
INNER JOIN [User] u ON f.StaffID = u.StaffID
WHERE f.CreatedDate >= @DateFrom
AND f.CreatedDate <= @DateTo
AND
(
@HasResponses IS NULL
OR
(
@HasResponses = 1 AND
(
SELECT COUNT(*)
FROM FeedbackResponse fr
WHERE fr.FeedbackID = f.ID
) > 0
)
OR
(
@HasResponses = 0 AND
(
SELECT COUNT(*)
FROM FeedbackResponse fr
WHERE fr.FeedbackID = f.ID
) = 0
)
)