This is the estimated probability of SAH pre-CT test, given the entered patient characteristics.
Patient's current probability of SAH:
This is the estimated probability of SAH post-CT test (negative result), given the entered patient characteristics.
This is the estimated minimum probability of SAH at which advantages of LP for assessment of SAH outweigh disadvantages, given the entered patient characteristics.
Prototype SAH Calculator
When subarachnoid hemorrhage (SAH) is concerning in an emergency context, a negative result from non-contrast cranial computer tomography (CT) is typically followed by lumbar puncture (LP) and diagnostic assessment of xanthrochromia in cerebrospinal fluid.
This calculator is an unvalidated prototype version of a calculator for estimating post-CT probability of SAH, given patient characteristics, as well as the probability of complications from LP and/or false xanthochromia results; these measures can be used to recommend whether LP is indicated.
This is a prototype calculator for demonstration purposes only. It has not been completed or validated. It should not be used as evidence in forming any medical assessments or decisions.