Patient selection: initial episode of shock associated with dengue fever
Parameters:
(1) “admission day” (number of days between day of fever onset and day of hospital admission)
(2) purpura and/or ecchymosis
(3) ascites and/or pleural effusion
(4) platelet count
(5) pulse pressure (= systolic minus diastolic blood pressure)
|
Parameter
|
Finding
|
Points
|
|
purpura and/or ecchymosis
|
no
|
0
|
|
|
yes
|
50
|
|
ascites and/or pleural effusion
|
no
|
0
|
|
|
yes
|
150
|
total score =
= (points for purpura/ecchymosis) + (points for ascites/pleural effusion) – (40 * (number of admission days)) – (7 * (platelet count) / 10000) – (4 * (pulse pressure))
Interpretation:
• The scores in the study ranged from –406 to +53.
• A score > - 154.4 was associated with a risk for recurrent shock.
Performance:
• The sensitivity was 68% and specificity 68%.
• The area under the ROC curve was given oas 0.73.
The decision rule was derived from the following equation (by multiplying each parameter by 100; by using 0.7 for the platelet parameter and dividing the platelet count by 1000 or using the coefficient for the platelet count in SIU; by dropping the constant):
X =
= (-0.4379 * (day of admission)) + (0.5207 if purpura/ecchymosis) + (1.4976 if ascites or pleural effusion) – (0.0069 * (platelet count) / 1000) – (0.0401 * (pulse pressure)) + 0.8385
probability of recurrent shock =
= 1 / (1 + EXP((-1) * X))
