Q says "in hospital"
There is no 'a' added.
Therefore, I would search through the various meanings/uses of hospital to derive alternative ideas of what Q could mean by that statement.
I am the type of person who looks as much at what Q does not say in statements as much as what Q does say. Q's statements are deliberately structured to lead people into assuming what is being said. Questions following each other are assumed to be related or hinting at the 'correct' answer to the question above. While this 'lead' meaning is intentional and necessary to what Q's aims are - it is not necessarily the way to get useful information from a Q post.