Risk Score of Ma et al for Early-Onset Peritonitis in a Patient Starting Peritoneal Dialysis

Patient selection: starting peritoneal dialysis

 

Parameters:

(1) age in years

(2) diastolic blood pressure in mm Hg

(3) serum sodium in mmol/L

(4) serum ALT in IU/L

(5) serum AST in IU/L

(6) serum total protein in g/L

(7) ESR in mm in first hour

(8) WBC count per microliter

(9) serum triglyceride in mmol/L

(10) serum magnesium in mmol/L

(11) serum total cholesterol in mmol/L

(12) fasting blood glucose in mmol/L

(13) heart rate in beats per minute

(14) left ventricular ejection fraction in percent

(15) blood urea nitrogen in mg/dL

(16) serum potassium in mmol/L

(17) serum LDL in mmol/L

(18) systolic blood pressure in mm Hg

(19) serum HDL in mmol/L

(20) carbon dioxide combining power in mmol/L

 

points for age =

= (0.2117308 * (0.01 * ((age)^2))) - (0.1141053 * (0.01 * ((age)^2)) * LN((age)/10))

 

points for diastolic blood pressure =

= (0.3894896 * (((DBP)/100)^3)) - (1.205053 * (((DBP)/100)^3) * LN((DBP)/100))

 

points for serum sodium =

= (-1.118932 * (((sodium)/100)^(-2))) - (0.4350019 * (((sodium)/100)^(-2)) * LN((sodium)/100))

 

 

Parameter	Finding	Points
serum ALT	< 15 U/L	0
	>= 15 U/L	-0.4272603
serum AST	< 17 U/L	0
	>= 17 U/L	-0.3352946
serum total protein	< 58 g/L	0
	>= 58 g/L	0.3829204
ESR	< 28 mm in first hour	0
	>= 28 mm in first hour	0.3119003
WBC count	< 6,000 per µL	0
	>= 6,000 per µL	-0.1684228
serum triglyceride	< 1.26 mmol/L	0
	>= 1.26 mmol/L	-0.3836425
serum magnesium	< 0.98 mmol/L	0
	>= 0.98 mmol/L	0.4827478
serum total cholesterol	< 4.43 mmol/L	0
	>= 4.43 mmol/L	-0.0654031
fasting blood glucose	< 5.0 mmol/L	0
	>= 5.0 mmol/L	-0.9677222
heart rate	< 80 beats per minute	0
	>= 80 beats per minute	-0.3486695
LV ejection fraction	> 60%	0
	<= 60%	-0.3853148
serum BUN	< 24 mg/dL	0
	>= 24 mg/dL	0.6670026
serum potassium	< 4.3 mmol/L	0
	>= 4.3 mmol/L	0.0730316
serum LDL	< 2.6 mmol/L	0
	>= 2.6 mmol/L	0.1397471
systolic blood pressure	< 145 mm Hg	0
	>= 145 mm Hg	0.0053947
serum HDL	> 1.1 mmol/L	0
	<= 1.1 mmol/L	0.0336835
carbon dioxide combining power	< 22.3 mmol/L	0
	>= 22.3 mmol/L	0.430856

 

where:

• In the implementation HDL and LDL are assumed to be HDL and LDL cholesterol. Values given in the paper for these parameters are close to values for total cholesterol.

 

total score =

= SUM(points for all of the parameters) - 1.578509

 

probability of peritonitis =

= 1 / (1 + EXP((-1) * (score)))

 

Performance:

• The area under the ROC curve is 0.76.