Allen developed a prognostic score in 1984 to predict functional independence for a patient who has had an acute stroke. The author was from Guy's Hospital in London.
Patient selection:
(1) age < 76 years
(2) Those who survived the first 24 hours after the stroke.
|
Parameter |
Standardized Coefficient |
Points |
|
complete limb paralysis |
-0.59469 |
-12 |
|
higher cerebral dysfunction + hemiplegia + hemianopia |
-0.46938 |
-11 |
|
drowsy or comatose after 24 hours |
-0.44016 |
-10 |
|
age in years |
-0.39524 |
(0.4 * (age)) |
|
loss of consciousness at onset of deficit |
-0.34554 |
-9 |
|
uncomplicated hemiparesis |
+0.34371 |
+8 |
|
constant |
|
+40 |
after Allen, Table 7 page 478
where:
• Complete limb paralysis = MRC scale 1 (muscle flickers when attempting to move) or 0 (no movement whatsoever); the complete MRC scale is listed above with the Orpington prognostic score
• Higher cerebral dysfunction = aphasia (difficulty in word finding) and/or parietal deficit (sensory or visual inattention, visuospatial neglect, or joint position sense loss)
• hemiplegia = paralysis of one side of the body
• hemianopia = homonymous visual field deficit to confrontation
• hemiparesis = muscle weakness affecting one side of the body
prognostic score =
= SUM(points for the findings present)
Interpretation:
• minimum score: -40
• maximum score: +40
• The higher the prognostic score, the better the functional independence.
• Scores indicating risk of poor outcome: <= 0 (all minus numbers)
• Good outcome = return to functional independence.
• Poor outcome = functional dependence or death
Criteria for poor outcome at 6 months was one of the following:
(1) death
(2) Barthel score < 13 out of 20
|
Threshold |
Sensitivity for Poor Outcome |
Specificity for Poor Outcome |
Likelihood Ratio |
|
30 |
100% |
1% |
1.01 |
|
20 |
97% |
10% |
1.08 |
|
10 |
85% |
42% |
1.46 |
|
0 |
72% |
63% |
1.97 |
|
-10 |
57% |
83% |
3.31 |
|
-20 |
34% |
95% |
6.62 |
|
-30 |
19% |
98% |
9.53 |
|
Score |
Probability of Functional Independence |
|
<= -25 |
0 |
|
-22.5 |
0.6 |
|
-20 |
1.2 |
|
-17.5 |
2.7 |
|
-15 |
6.4 |
|
-12.5 |
11.3 |
|
-10 |
15.8 |
|
-9.33 |
17.5 |
|
-7.5 |
28.4 |
|
-5 |
37.5 |
|
-2.67 |
50 |
|
-2.5 |
52.5 |
|
0 |
64 |
|
2.5 |
74.1 |
|
4 |
82.5 |
|
5 |
85.2 |
|
7.5 |
91.1 |
|
10 |
94.9 |
|
12.5 |
97.1 |
|
15 |
97.6 |
|
17.5 |
98.9 |
|
20 |
99.1 |
|
>= 22.3 |
100 |
from Figure page 479
This can be approximated (using JMP) by the following:
|
Score |
Probability of Functional Independence |
|
>= 22.3 |
100% |
|
> 4 to < 22.3 |
(0.005359 * ((score)^3)) + (-0.2843 * ((score)^2)) + (5.212 * (score)) + 65.75 |
|
>= -9.33 to <= 4.0 |
(4.811 * (score)) + 63.14 |
|
> -25 to < -9.33 |
0.08539 * ((score)^2)) + (4.0417 * (score)) + 47.86 |
|
<= -25 |
0 |
Limitations:
• This score was developed over 15 years ago, and it does not include the effect of thrombolytic therapy. However, it can serve as an estimate of the untreated prognosis.
Specialty: Neurology
ICD-10: ,
