Ackroyd et al reported a preoperative score for predicting the need for blood transfusion in a woman undergoing hysterectomy for ovarian cancer. The authors are from Temple University and Fox Chase Cancer Center.
Patient selection: prior to hysterectomy for ovarian cancer
Outcome: packed red blood cell transfusion from during surgery up to 30 days after
Parameters:
(1) age in years
(2) race
(3) ascites at presentation
(4) preoperative hematocrit in percent
(5) preoperative platelet count in 10^9/L
(6) disseminated cancer
(7) type of hysterectomy
(8) large bowel resection or exenteration anticipated
|
Parameter
|
Finding
|
Points
|
|
age
|
< 65 years
|
0
|
|
|
>= 65 years
|
1
|
|
race
|
white
|
0
|
|
|
African American
|
1.25
|
|
|
other
|
1
|
|
ascites
|
no
|
0
|
|
|
yes
|
1.25
|
|
hematocrit
|
>= 37%
|
0
|
|
|
33 to 36.9 percent
|
1.5
|
|
|
30 to 32.9
|
3
|
|
|
< 30
|
4.5
|
|
platelet count
|
< 400 * 10^9/L
|
0
|
|
|
>= 400 *10^9/L
|
1.25
|
|
disseminated cancer
|
no
|
0
|
|
|
yes
|
1
|
|
type of hysterectomy
|
laparoscopic
|
0
|
|
|
open
|
4
|
|
additional procedure
|
no
|
0
|
|
|
yes
|
3
|
total score =
= SUM(points for all of the paramters)
Interpretation:
• minimum score: 0
• maximum score: 17.25
• The higher the score the greater the risk of any blood transfusion.
From Figure 2:
X =
= (0.02033 * ((score)^2)) + (0.1471 * (score)) - 3.541
probability of blood transfusion =
= 1 / (1 + EXP((-1) * X))
Performance:
• The area under the ROC curve is 0.80.
