Tang et al reported a nomogram for predicting 30-day readmission for an older adult undergoing hip fracture surgery. The authors are from China Medical University and affiliated hospitals.
Patient selection: adult 60 to 100 years of age with surgical repair of hip fracture
Parameters:
(1) age in years, from 60 to 100 years
(2) history of prior stroke
(3) chronic liver disease
(4) treatment
(5) serum uric acid in mmol/L
(6) serum total protein in g/L
(7) serum albumin in g/L
(8) pneumonia
points for age =
= (0.258 * (age)) - 15.51
points for uric acid =
= 0.02 * (uric acid)
points for total protein =
= (0.977 * (protein)) - 29.31
points for serum albumin =
= 137.5 - (2.5 * (albumin))
|
Parameter
|
Finding
|
Points
|
|
history of prior stroke
|
no
|
0
|
|
|
yes
|
5.9
|
|
chronic liver disease
|
no
|
0
|
|
|
yes
|
9.4
|
|
treatment
|
0 (hemiarthroplasty)
|
15.8
|
|
|
1 (total hip arthroplasty)
|
11.8
|
|
|
2 (intramedullary nailing)
|
7.9
|
|
|
3 (multiple screws)
|
3.9
|
|
|
4 (plate/screw fixation)
|
0
|
|
pneumonia
|
no
|
0
|
|
|
yes
|
7.4
|
where:
• The nomogram gives numbers as identifiers for treatment, but the corresponding treatment is not mentioned. The assignment used is based on the data in Table II. In Figure 2B treatment 1 is referenced as total hip arthroplasty.
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 234.3
• The scores for total protein and albumin dominate the scoring.
value of X =
= (0.1268 * (score)) - 14.68
The authors also reported the value of X (logit) =
= (0.03 * (age)) + (0.703*(prior stroke)) + (1.047 * (CLD)) - (0.517 * (treatment number)) + (0.002 * (uric acid)) + (0.123 * (protein)) - (0.313 * (albumin)) + (0.797 *(pneumonia)) - 1.049
risk of 30-day readmission =
= 1/(1+EXP((-1) * X))
Performance:
• The area under the ROC curve was 0.88 in the derivation and 0.84 in the validation cohorts.
