FAST

And also when people are fast positive, it doesn't tell you what type of stroke they actually have because a stroke is a mixed group of patients of whom a proportion have a hemorrhage, a proportion have an ischemic stroke, but within that ischemic stroke population are then patients who benefit from different types of treatment.

And what we're particularly keen to find with our research is people who have this large vessel occlusion type of stroke.

And if you took a hundred patients who are suspected stroke by FAST in the ambulance population, within that hundred, there's probably only about between 10 and 12 who have large vessel occlusion stroke.

But they're really important to find because those are the patients if you get into a thrombectomy very quickly, then you can make a huge difference in terms of their future disability.

However, Many patients, about two thirds of patients in the UK, their local stroke hospital, it won't provide thrombectomy.

So of course, we still potentially get false positive tests.

We potentially get false negative tests, but our work that we've done so far shows that it can narrow that population of patients who've just got stroke symptoms into a group where it's more likely that there are large vessel occlusion stroke patients within it and could be more appropriate to then take to a regional thrombectomy centre directly rather than simply the nearest stroke unit.

So just looking at what the standard of practice now and to your point, Chris, around the reliance on tools such as the FAST test or indeed the ROSIA test, the recognition of stroke in the emergency room, and then trying to articulate, is it an anterior stroke? Is it a posterior? Are we missing posterior symptoms? But absolutely using this in sequence.