Wong et al developed a model for identifying clinically significant bleeding in an adult with dengue fever. This can help to identify a patient who may benefit from more aggressive management. The authors are from Tan Tock Seng Hospital, Nanyang Technological University, and the National University of Singapore in Singapore.
Patient selection: adult with dengue fever
Outcome: clinically significant bleeding
Parameters on admission:
(1) gender
(2) temperature in °C
(3) nausea and/or vomiting
(4) absolute neutrophil count (ANC) in 10^9/L
(5) absolute lymphocyte count (ALC) in 10^9/L
(6) hematocrit in percent from 0 to 100
(7) platelet count in 10^9/L
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Parameters
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Finding
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Points
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gender
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female
|
0
|
|
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male
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-1.05
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temperature
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<= 38°C
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0
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|
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> 38°C
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0.59
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nausea and vomiting
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absent
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0
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|
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present
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0.3
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Parameter
|
Points
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absolute neutrophil count (ANC)
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0.27 * (ANC)
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|
absolute lymphocyte count (ALC)
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0.9 * (ALC)
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|
hematocrit
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-0.04 * (hematocrit)
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platelet count
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-0.007*(platelet count)
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where:
• Female gender had an adjusted odds ratio of 2.85. The LN(female) was 1.05.
• The absolute lymphocyte count had an adjusted odds ratio of 0.4. The LN(ALC) was -0.9.
X = log odds =
= SUM(points for all 7 parameters) - 0.04
probability of clinically significant bleeding =
= 1 / (1 + EXP((-1) * X))
Interpretation:
• A log odds > -3.919 was used to identify a patient at risk for significant bleeding. This corresponds to a risk of 2%.
Performance:
• The area under the ROC curve was 0.76.
• The sensitivity was 0.87 and the specificity 0.38. The negative predictive value was 0.98.
