Acute stroke admission and diagnostic procedures according to the hour and day of onset: the SIRIO collaborative data.

Background: Variations in stroke onset are related to stroke type and severity. We evaluated the impact of hourly and daily stroke onset variations on the pattern of patient hospital referral and on the time interval from stroke onset to hospital admission and brain neuroimaging investigations.

Methods: This multicenter observational study recorded all incident acute strokes within a 4-month period.

Results: One hundred and three participating centers collected data on 3,018 stroke cases. Stroke onset was more frequent on Mondays and between 08.00 and 10.59 h. Median time to admission after symptom onset was higher on Fridays (173.5 min) and between 20.00 and 22.59 h (207 min). Rescue by ambulance was associated with a greater stroke severity. Median time from hospital admission to brain neuroimaging investigations was higher on Saturdays (178.5 min) and between 23.00 and 10.59 h when the most severe strokes were hospitalized.

Conclusions: The pattern of patient hospital referral and the time interval from stroke onset to hospital admission and brain neuroimaging investigations varied widely according to the hour and weekday of onset as well as to the reduced availability of hospital resources. An adequate distribution of the available resources should be planned in order to meet the demand.