Eek. Greater sharing of data is often cause for concern. But this seems like a particularly pernicious change. For those who are unaware, the NHS will currently treat anyone who needs care: no questions asked, including about illegal activity (as long as you're not judged a danger to medical staff or other patients of course). And they won't report any suspected illegal activity to the police either.
This is excellent from a healthcare perspective. It means that if someone needs care they don't have to think twice about it. They can just seek that care. This looks like it might destroy that trust, and IMO that's not at all worth it.