Perhaps Sqad didn't see the post.
In recent years, my son has been the type of patient that doctors might get fed up with. He is desperate to find out what is wrong with him and keeps asking the docs to refer him to some new specialist. They used to refuse and basically tell him he's got to live with it, but there's been a bit more movement of late, where I think they are agreeing just to get him off their backs. So if you really think you need a test, Hypo, badger your GP or their partners.
Back to the OP, I would think most hypochondriacs die of something other than the thing they were fearing. Why not ask the FOI people, anyway?