Age should be entered as the patient's age in years.

Hypertension should be defined or considered present if there is a known history of hypertension, the patient was taking antihypertensive medications prior to admission or there are other clinically apparent signs consistent with essential hypertension such as very high blood pressure on admission or electrocardiogram, echocardiogram, kidney or other end-organ signs or laboratory findings consistent with a history of hypertension.

Neurological or clinical grade of the patient is based on the grade when they are admitted to hospital and prior to aneurysm repair. This model includes studies that determined the neurological grade before aneurysm repair but before and after resuscitation including insertion of an external ventricular drain. Thus, you should use the neurological grade determined before aneurysm repair. The model uses the World Federation of Neurological Surgeons (WFNS) scale that is based on the modified Glasgow coma score and presence or absence of focal motor deficit (including aphasia) as outlined below.{Teasdale, 1988 #17556;Drake, 1988 #8208;Teasdale, 1974 #34155} If the Hunt and Hess system is used, an approximate conversion method is shown.{Hunt, 1968 #10458}

Size is defined as the largest diameter of the aneurysm. This is usually the length from the aneurysm neck at the aneurysm origin from the parent artery to the end of the dome of the aneurysm.

Location follows the ISAT categorization as such:
ACA - Anterior cerebral artery, including Anterior communication, proximal to A comm, pericallosal.
ICA - Internal carotid artery, including proximal to or ophthalmic region, posterior communication region, and the bifurcation.
MCA - Middle cerebral artery.
PCA - Posterior circulation artery, including vertebro-basilar artery and branches.

Fisher grade should be calculated using the cranial computed tomographic scan obtained when the patient presented with subarachnoid hemorrhage and before aneurysm repair:
1 - No SAH or intraventricular hemorrhage.
2 - Diffuse deposition of thin layer with all vertical layers of blood (interhemispheric fissure, insular cistern, ambient cistern) < 1 mm thick.
3 - Vertical layers of blood ≥1 mm thick or localized clots (clots defined as > 3 x 5 mm).
4 - Diffuse or no subarachnoid blood, but with intracerebral or intraventricular clots.

Method of repair indicates whether the ruptured aneurysm was repaired by neurosurgical clipping, endovascular coiling or not repaired. The data from which this model is constructed leads to the recommendation that aneurysms repaired with adjunctive surgical methods in addition to clipping including bypass and trapping are classified as neurosurgical clipping and stent-assisted coiling, flow diverters and such are classified as endovascular coiling.

Admission Characteristics




Interpreting Results

After inputting known characteristics, the Results section will load between 1 and 3 graphs consisting of 3 bars. The first illustrates the probability of mortality, the second of an unfavourable outcome and the third of a favourable outcome. The description below each graph outlines the corresponding confidence intervals for the mortality and unfavourable outcome graphs.