Prognostic Score of Emparanza et al in Acute Meningococcemia

 

Parameters:

(1) coma

(2) base excess

(3) platelet count

(4) glucose

(5) temperature

(6) WBC

(7) sex

(8) purpura

(9) WBC in CSF

Parameter	Finding	Points
coma	absent (Glasgow Coma Score >= 8)	0
	Glasgow coma score < 8	1
sex	male	0
	female	1
purpura	absent	0
	present	1

 

discriminant function =

= (-4.764 * (coma)) + (0.433 * (base excess)) - (0.00001 * (platelet count)) + (0.0777 * (glucose)) - (1.342 * (temperature)) + (0.0001 * (WBC)) - (2.548 * (sex)) - (4.075 * (purpura)) - (0.0003 * (CSF WBC)) + 59.778

 

The units for the laboratory values are not stated in the original paper (and no clarification could be found in subsequent issues of journal):

(1) base excess: since mEq/L and mmol/L are equivalent, either should do

(2) platelet count: assume count per µL; values as 10^3/L or 10^9/L gave apparently unusable values

(3) glucose: assume use conventional units (mg/dL); SIU values in mmol/L seem too small after multiplied by factor

(4) temperature: assume temperature in °C

(5) WBC: assume count per µL; values using 10^3/µL or 10^9/L gave apparently unusable values

(6) CSF WBC: assume cells/µL

 

Interpretation:

 

Discriminant Function Value	Outcome
> 0 (positive)	survival
0	borderline
< 0 (negative)	death

 

Comments: The platelet count is counterintuitive; most other studies associate a low platelet count with poor prognosis. Using a negative factor causes the negative influence to increase as count rises.