Feng et al reported a model for predicting complicated appendicitis in an older adult. This can help to identify a patient who may require more aggressive management. The authors are from Anhui University of Chinese Medicine in China.
Patient selection: age >= 65 years of age
Complicated appendicitis: acute gangrenous, perforated, and/or with periappendiceal abscess
Parameters:
(1) abdominal pain duration (APD) in hours from 0 to 100
(2) peritonitis
(3) serum total bilirubin in µmol/L, from 0 to 35
points for abdominal pain duration =
= (0.375 * (hours))
points for serum total bilirubin =
= (2.857 * (bilirubin))
|
Parameter
|
Finding
|
Points
|
|
peritonitis
|
no
|
0
|
|
|
yes
|
9.1
|
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 146.6
• The change in probability from 10 to 90% occurs over a score range from 64 to 83.
value of X =
= (0.236 * (score)) - 17.39
probability of complicated peritonitis =
= 1 / (1 + EXP((-1) * X))
Performance:
• The authors claim an area under the ROC curve of 0985.
