Table 2.

The components of the Ottawa and Emerald subarachnoid haemorrhage rules and their distribution within the cohort

Ottawa subarachnoid haemorrhage rule
 Age ≥40 years210
 Neck pain or stiffness95
 Witnessed loss of consciousness42
 Onset during exertion32
 Thunderclap headache39
 Limited neck flexion on examination14
 Ottawa positive288
Emerald subarachnoid haemorrhage rule
 Systolic blood pressure >150 mmHg82
 Diastolic blood pressure >90 mmHg80
 Blood glucose >115 mg/dL (>6.4 mmol/L)96
 Serum potassium <3.9 mEq/L193
 Emerald positive267