The SCAN rule: a clinical rule to reduce CT misdiagnosis of intracerebral haemorrhage in minor stroke

Many patients with minor stroke are referred to outpatient clinics and are not scanned immediately. A clinical rule is needed to identify patients who are likely to have intracerebral haemorrhage (ICH) and require urgent brain imaging and patients who can safely start antiplatelet agents before scanning.MethodsClinical factors associated with ICH were determined in 334 consecutive patients with minor stroke (National Institute of Health Stroke Scale score ≤3), and a predictive model for ICH that was validated in a cohort of 280 patients presenting to a hospital–stroke clinic was derived. Prognostic value was quantified as the area under the ROC curve (c statistics).ResultsThe proportion of ICH in minor stroke was 5.1% (95% CI 3.2% to 8.0%) in OXVASC, and 5.4% (3.3% to 8.7%) in the clinic cohort. Clinical factors predictive of ICH in OXVASC included blood pressure on initial assessment ≥180/110 mm Hg (OR 14.5, 95% CI 1.8 to 114, p=0.001), vomiting (OR 15.7, 95% CI 5.4 to 46, p