Fu et al reported preoperative models for predicting outcomes after hip arthroplasty for a femoral neck fracture in an elderly Asian adult. One model predicts 1-year mortality. The authors are from Guangdong Academy of Medical Sciences in China.
Patient: Asian patient >= 65 years old with femoral neck fracture
Outcome: 1-year mortality
Parameters:
(1) Charlson comorbidity index (CCI)
(2) preoperative electrocardiogram
(3) preoperative chest radiograph
(4) preoperative walking ability
(5) dementia
(6) age in years, from 55 to 100
(7) serum albumin in g/L, from 20 to 65
points for age =
= (0.5578 * (age)) - 30.6778
points for serum albumin =
= 144.444 - (2.222 * (albumin))
|
Parameter
|
Finding
|
Points
|
|
Charlson comorbidity index
|
<= 4
|
0
|
|
|
> 4
|
10.83
|
|
electrocardiogram
|
normal
|
0
|
|
|
abnormal
|
22
|
|
chest X-ray
|
normal
|
0
|
|
|
abnormal
|
25.65
|
|
walking ability
|
free walking
|
0
|
|
|
needs assistance
|
44.75
|
|
|
bedridden
|
48.17
|
|
dementia
|
no
|
0
|
|
|
yes
|
18.81
|
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 5.58 (nomogram >= 55 year of age but study population >= 65)
• maximum score: 250.50
• The higher the score the greater the risk of 1-year mortality.
value of X =
= (0.0392 * (score)) - 7.743
probability of 1 year mortality =
= 1 / (1 + EXP((-1) * X))
Performance:
• The bias corrected C-index is 0.79 for the derivation and 0.77 for the validation cohorts.
