Key Message
The new ICD-11 stroke definition will capture new strokes that are currently labelled as TIAs, increasing projected stroke incidence by approximately 4.2% uniformly across all four UK nations, an estimated 2,771 additional cases per year. The greatest absolute burden will fall on regions with older populations (rural Scotland, Wales, South West England), while projected rates in this analysis might be overestimated by 10–14% in predominantly White regions due to the ethnic diversity of our South London source population. This diagnostic change is happening alongside a broader rise in stroke incidence driven by inequalities in cardiovascular risk, a trend that is larger and potentially modifiable. Planning for ICD-11 must address both.