Weiss and Bernstein proposed a risk factor score to identify women at risk for venous thromboembolism related to pregnancy. The authors are from Albert Einstein College of Medicine in New York City.
Risk factors identified in obstetric patients:
(1) history of previous deep vein thrombosis or pulmonary embolism
(2) age in years
(3) Caesarean delivery
(4) body mass index in kilograms per square meter
(5) infection
(6) postpartum oral contraceptive use
(7) blood type
(8) history of previous abdominal or pelvic surgery
(9) fracture
(10) trauma
(11) prolonged bed rest
(12) chronic medical condition
(13) personal or family history of hereditary thrombophilia
|
Risk Factor |
Finding |
Points |
|
history of previous deep vein thrombosis or pulmonary embolism |
yes |
4 |
|
|
no |
0 |
|
age in years |
>= 35 |
1 |
|
|
< 35 |
0 |
|
Caesarean delivery |
yes |
1 |
|
|
no |
0 |
|
body mass index in kilograms per square meter |
> 29 |
1 |
|
|
<= 29 |
0 |
|
infection |
yes |
1 |
|
|
no |
0 |
|
postpartum oral contraceptive use |
yes |
1 |
|
|
no |
0 |
|
blood type |
A, B, AB |
1 |
|
|
O |
0 |
|
history of previous abdominal or pelvic surgery |
yes |
1 |
|
|
no |
0 |
|
fracture |
yes |
1 |
|
|
no |
0 |
|
trauma |
yes |
1 |
|
|
no |
0 |
|
prolonged bed rest |
yes |
1 |
|
|
no |
0 |
|
chronic medical condition |
yes |
1 |
|
|
no |
0 |
|
personal or family history of hereditary thrombophilia |
yes |
1 |
|
|
no |
0 |
risk factor score =
= SUM(points for risk factors)
Interpretation:
• minimum score: 0
• maximum score: 16
• A risk score > 2 is associated with an increased risk of thromboembolic event (odds ratio 4.8).
Performance at cutoff point:
• sensitivity 21%, specificity 95%, positive predictive value 57%, negative predictive value 78%
• specific but not terribly sensitive, with low predictive values
• The performance might be improved by changing the points assigned for risk factors, adding more factors, or using laboratory tests if any risk factor is present.
Specialty: Hematology Oncology, Clinical Laboratory
