Naidech et al developed a nomogram for predicting the risk of rebleeding from an intracranial aneurysm. This was based on the Hunt-Hass grade for the initial subarachnoid hemorrhage and the diameter of the aneurysm. The authors are from the College of Physicians and Surgeons of Columbia University in New York City.
Parameters:
(1) Hunt-Hess (HH) grade for the initial subarachnoid hemorrhage
(2) diameter of the aneurysm in mm
|
Diameter in mm
|
HH Grade I
|
HH Grade II
|
HH Grade III
|
HH Grade IV
|
HH Grade V
|
|
0
|
0.01
|
0.03
|
0.05
|
0.08
|
0.14
|
|
10
|
0.02
|
0.04
|
0.07
|
0.13
|
0.21
|
|
15
|
0.03
|
0.06
|
0.1
|
0.17
|
0.27
|
|
20
|
0.04
|
0.08
|
0.14
|
0.21
|
0.34
|
|
25
|
0.06
|
0.1
|
0.18
|
0.27
|
0.41
|
|
30
|
0.08
|
0.14
|
0.23
|
0.34
|
0.48
|
|
35
|
0.11
|
0.18
|
0.28
|
0.41
|
0.56
|
|
40
|
0.14
|
0.22
|
0.34
|
0.49
|
0.64
|
from Figure 2, page 413
If this data is modeled in JMP:
probability of rebleeding if the initial bleed was HH Grade I =
= (0.0000835 * ((diameter in mm)^2)) - (0.000132 * (diameter in mm)) + 0.0111765
probability of rebleeding if the initial bleed was HH Grade II =
= (0.0001182 * ((diameter in mm)^2)) + (0.0000756 * (diameter in mm)) + 0.0296078
probability of rebleeding if the initial bleed was HH Grade III =
= (0.000144 * ((diameter in mm)^2)) + (0.0016611 * (diameter in mm)) + 0.0460784
probability of rebleeding if the initial bleed was HH Grade IV =
= (0.0001772 * ((diameter in mm)^2)) + (0.0032094 * (diameter in mm)) + 0.079902
probability of rebleeding if the initial bleed was HH Grade V =
= (0.0001342 * ((diameter in mm)^2)) + (0.0074244 * (diameter in mm)) + 0.1337255
