Setting and Population
The model was populated with data collected in 3 participating Trusts;
2 hospitals, and 1 ambulance service. The process of recruitment and
data collection has been described in detail previously.19 The population
of interest were patients admitted with stroke or strokelike symptoms
during a 12-month period between August 1, 2010, and July 31,
2011. Both participating hospital Trusts offered a 24-hour thrombolysis
service, 7 days a week, but in the case of the second Trust, this was
achieved by combining an in-hours service, 9 am to 5 pm, Monday to
Friday, in the lead hospital with out-of-hours care at a separate site.
The prevalence of stroke in West Midlands is estimated to be in the
region of 17 per 1000 population, similar to national rates.20
Participating patients were consented to allow identifiable data to be
recorded and linked between that collected by EMS and each hospital
site. Recruitment was focused on patients attending the 2 main hospital
sites but included those patients attending the subsidiary site after hours
who would have presented at the lead hospital if a 24-hour service was
available. These data were collected as part of an anonymized case note
review and were therefore not linked to the EMS records.