Model Pathways
The model was constructed to follow the care pathway of individuals
presenting to hospital with a suspected stroke (Figure). The patient
characteristics (age, sex, ethnicity) and route to hospital were
based on patient-level data collected from participating hospitals (see
below). All patients who entered the model were assumed to have
been admitted via the hospital emergency department and could have
arrived via the Emergency Medical Services (EMS), referred by a
general practitioner, travelled via private transport, transferred from
another hospital, or to have had a stroke as an existing inpatient. It
was assumed that once in hospital, all patients with suspected stroke
would receive a CT scan. Patients were dichotomized by the results
of this scan (ie, whether they had an ischemic or hemorrhagic stroke),
and those with ischemic stroke were considered potentially eligible
for thrombolysis.3,16,17 Patients found not to have had a stroke were
considered to be stroke mimics. These patients were assumed not to
have received thrombolysis, and only costs incurred by transport and
initial assessment in hospital (CT scan) were modeled. Life expectancy
and therefore the model time horizon varied depending on whether