Patient selection: medical patient in the Emergency Department
Parameters:
(1) sex
(2) respiratory rate in breaths per minute
(3) oxygen saturation in percent
(4) duration of illness in days, from 0 to 45
(5) Glasgow coma scale (GCS), from 3 to 15
(6) admission to the ICU
(7) serum urea in mmol/L
(8) serum albumin in g/L
NOTE: The nomogram does not reflect the information shown in Model 2. For example, a GCS of 15 and oxygen saturation of 100% are associated with mortality. Similarly, a respiratory rate of 0 and serum albumin of 5 g/L is associated with survival. There appears to be a problem.
Model as Written
|
Parameter
|
Finding
|
Points
|
|
sex
|
female
|
13.127
|
|
|
male
|
0
|
|
ICU admission
|
no
|
55.598
|
|
|
yes
|
0
|
points for albumin =
= (1.4826 * (albumin)) - 7.4131
points for duration =
= (2.2222 * (days))
points for GCS =
= (4.5683 * (GCS)) - 13.705
points for oxygen saturation =
= (0.942 * (oxygen sat)) - 47.1
points for respiratory rate =
= (-1.3446 * (rate)) + 87.4
points for urea =
= (-0.8037 * (urea)) + 88.41
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 528
• The higher the score the greater the risk of mortality.
X =
= (0.000001943 * ((score)^3)) - (0.001911 * ((score)^2)) + (0.6553 * (score)) - 75.48
|
Score
|
Mortality Risk
|
|
< 206.56
|
< 1%
|
|
206.56 to 388.03
|
1 / (1 + EXP((-1) * X))
|
|
> 388.05
|
> 99%
|
Correction: Substitute Survival for Mortality
Option 1: The mapping for the nomogram should be to survival risk rather than mortality. Then
mortality risk =
= 1 - (survival risk)
Option 2: The point assignment is the opposite of what it should be, but this would be less likely
|
Parameter
|
Finding
|
Points
|
|
sex
|
male
|
13.127
|
|
|
female
|
0
|
|
ICU admission
|
yes
|
55.598
|
|
|
no
|
0
|
points for albumin =
= (-1.4826 * (albumin)) + 88.957
points for duration =
= ( -2.2222* (days)) + 100
points for GCS =
= (-4.5683 * (GCS)) + 68.525
points for oxygen saturation =
= (-0.942 * (oxygen sat)) + 94.2
points for respiratory rate =
= (1.3446 * (rate))
points for urea =
= (0.8037 * (urea))
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 528
• The higher the score the greater the risk of mortality.
X =
= (0.000001943 * ((score)^3)) - (0.001911 * ((score)^2)) + (0.6553 * (score)) - 75.48
|
Score
|
Mortality Risk
|
|
< 206.56
|
< 1%
|
|
206.56 to 388.03
|
1 / (1 + EXP((-1) * X))
|
|
> 388.05
|
> 99%
|
