Hospital-discharge-data underestimate hemorragic stroke events: data from a multicenter validation survey in the Florence area (Italy).

Patients with Hemorrhagic Stroke (HS) are often selected for epidemiological reporting, research, and surveillance using Hospital Discharge Records (HDR), that reflect real-world practice both at hospital and population level. Moreover, HDR are the only source of information everywhen ad-hoc registration systems are not affordable. Obtaining reliable information requires that stroke diagnoses in hospital discharge data are correct, but, at variance with several cardiac events, stroke remains difficult to classify reliably