Lu et al reported a model for predicting surgery-related pressure ulcers in cardiovascular surgical patients. This can help to identify patients to target for pressure ulcer prevention. The authors are from Nantong University in Jiangsu, China.
Patient selection: cardiovascular surgical patient
Parameters from nomogram:
(1) therapy with corticosteroids
(2) surgical duration in minutes
(3) body weight in kilograms
(4) cardiovascular disease category
points for surgical duration =
= (0.01478 * (duration)) + 0.005726
points for weight =
= (0.08921 * (weight)) - 0.004465
Parameter |
Finding |
Points |
therapy with steroids |
no |
0 |
|
yes |
3.8 |
disease category |
congenital heart disease |
0 |
|
thoracic aortic aneurysm |
5.3 |
|
valvular disease |
5.6 |
|
coronary heart disease |
6.6 |
total score for nomogram =
= SUM(points for all of the parameters)
value of X =
= (0.3297 * (score)) - 5.247
probability of pressure ulcer from nomogram =
= 1 / (1 + EXP((-1) * X))
Alternatively, the logistic regression model in Table 3 is:
Parameter |
Finding |
Points |
therapy with steroids |
no |
0 |
|
yes |
1.241 |
disease category |
congenital heart disease |
0 |
|
thoracic aortic aneurysm |
1.747 |
|
valvular disease |
1.861 |
|
coronary heart disease |
2.174 |
duration |
|
0.005 * (duration) |
weight |
|
-0.029 * (weight) |
Y =
= SUM(points for parameters) - 2.235
probability of pressure ulcer =
= 1 / (1 + EXP((-1) * Y))
However, the logistic regression model gives results discrepant from the nomogram. The coefficient may need review.
Specialty: Dermatology