Table 1 Summary of clinical outcome states and their reference standards

Complex

Ischaemic stroke with large vessel occlusion

CT/MR angiography assessed by blinded neuro-radiologist. LVO defined as a Ten Point Clot Burden Score <10.

Large volume intracerebral haemorrhage

Brain imaging assessed by blinded neuro-radiologist. Haematoma volume of at least 60ml in a single cerebral hemisphere.

Prior territorial stroke

Brain imaging assessed by blinded neuro-radiologist. Appropriate changes in either cerebral hemisphere.

Symptomatic severe anterior vessel stenosis

CT/MR angiography assessed by blinded neuro-radiologist which shows ≥ 70% narrowing of any large branch of the anterior cerebral circulation (ICA or MCA) without occluding thrombus, the side of the focal neurological symptoms suffered by the patient is compatible with stenosis, the severity of focal symptoms is ≥ 6 on NIHSS.

Minor Stroke

Small / medium volume intracerebral haemorrhage

Brain imaging assessed by blinded neuro-radiologist. Haematoma volume < 60ml in a single cerebral hemisphere.

Ischaemic stroke without large vessel occlusion

Expert clinician diagnosis at 72 hours after hospital admission (or discharge/death if sooner), CTA/MRA confirms the absence of LVO (i.e. Clot Burden Score = 10), and CTA/MRA plus clinical findings confirm the absence of SSAVS.

Non Stroke

Transient ischaemic attack

Expert clinician diagnosis at 72 hours after hospital admission (or discharge/death if sooner) and brain imaging findings do not refute the clinician opinion or indicate the presence of one of the other acute outcomes.

Mimic condition

Expert clinician diagnosis at 72 hours after hospital admission (or discharge/death if sooner) and brain imaging findings do not refute the clinician opinion or indicate the presence of one of the other acute outcomes.