Iannuzzi et al developed a model for predicting postdischarge venous thromboembolism in a surgical patient. The study was based on data in the NSQIP database. The authors are from the University of Rochester.
Patient selection: surgical patient
Outcome: venous thromboembolism or pulmonary embolus following discharge
Major surgical complication: organ space infection, cardiac event, ventilator dependency, pneumonia, return to operating room, new onset renal insufficiency, stroke, coma, shock, bleeding, sepsis
Risk subscores:
(1) based on independent variables
(2) days from operation to discharge vs major complication
Parameters for the independent variables:
(1) age in years
(2) steroid use
(3) current smoker
(4) body mass index (BMI)
(5) preoperative dependent functional status
(6) operative time >= 100 minutes
|
Parameter |
Finding |
Points |
|
age in years |
< 58 years |
0 |
|
|
>= 58 years |
2 |
|
steroid use |
no |
0 |
|
|
yes |
4 |
|
current smoker |
no |
0 |
|
|
yes |
-1 |
|
body mass index |
< 30 kg per sq meter |
0 |
|
|
>= 30 kg per sq meter |
2 |
|
preoperative functional status |
no |
0 |
|
|
yes |
2 |
|
operative time |
< 100 minutes |
0 |
|
|
>= 100 minutes |
2 |
subscore =
= SUM(points for all 6 parameters)
|
Discharge Day |
Major Complication |
No Complication |
|
0 |
5 |
0 |
|
1 |
10 |
2 |
|
2 |
10 |
2 |
|
3 |
10 |
2 |
|
4 |
12 |
6 |
|
5 |
12 |
6 |
|
6 |
12 |
6 |
|
7 |
11 |
8 |
|
8 |
11 |
8 |
|
9 |
10 |
8 |
|
10 |
10 |
8 |
|
11 |
10 |
8 |
|
12 |
10 |
8 |
|
13 |
10 |
8 |
|
14 |
10 |
8 |
where:
• The point assignment for complications has 2 interpretations. One is as above with major complication counted only once. The other is to determine if a separate major complication occurs in each time interval (0 to 1, 1 to 3, 4 to 6, 7 to 8, 9 to 14). This could give a maximum subscore of 48.
• No mention is made for a discharge day > 14 days after surgery. One option is to exclude this group, which is what is used in the implementation. The second is to use the data for day 14.
total score =
= (points for independent variables) + (points for complication and discharge day)
Interpretation:
• minimum score: -1
• maximum score: 24
• The higher the score the greater the risk
|
Score |
Risk Group |
Percent with Thrombosis |
|
-1 to 8 |
low |
0.19% |
|
9 to 13 |
intermediate |
0.68% |
|
>= 14 |
high |
1.4% |
|
Score |
Percent with Thrombosis |
|
-1 to 1 |
0.07 |
|
2 or 3 |
0.14 |
|
4 |
0.17 |
|
5 |
0.2 |
|
6 |
0.3 |
|
7 or 8 |
0.35 |
|
9 |
0.5 |
|
10 |
0.6 |
|
11 or 12 |
0.7 to 0.8 |
|
13 |
0.9 |
|
14 |
1.1 |
|
15 |
1.5 |
|
16 |
1.3 |
|
17 |
InfoPurpose: To predict the probability of a surgical patient developing a venous thromboembolism (VTE) following discharge based on the study of Iannuzzi et al. Specialty: Hematology Oncology, Clinical Laboratory Objective: risk factors, severity, prognosis, stage ICD-10: I80, I81, I82, |
