Takeshita et al reported a nomogram for predicting testicular torsion in a Japanese adult with acute scrotal pain. This can help to identify a patient who may require aggressive management. The authors are from Saitama Medical Center and Saitama Medical University in Saitama, Japan.
Patient selection: Japanese male with acute scrotal pain
Parameters:
(1) testicular position abnormality
(2) difficulty walking
(3) time of day at onset
(4) ambient temperature in °C
|
Parameter
|
Finding
|
Nomogram Points
|
LR Equation
|
|
testicular position
|
normal
|
0
|
0
|
|
|
abnormal
|
100
|
5.085
|
|
difficulty walking
|
no
|
0
|
0
|
|
|
yes
|
48.7
|
2.502
|
|
time of day at onset
|
12 AM to 8 AM
|
47.6
|
2.352
|
|
|
other
|
0
|
0
|
|
ambient temperature
|
< 15°C
|
39
|
1.944
|
|
|
>= 15°C
|
0
|
0
|
total score for nomogram =
= SUM(points for all of the parameters)
total score for logistic regression model = Y =
= SUM(points for LR equation) - 4.015
Interpretation:
• minimum score: 0
• maximum score: 235.3
• The higher the score the more likely the diagnosis of torsion.
value of X =
= (0.05098 * (score)) - 4.034
probability of testicular torsion =
= 1 / (1 + EXP((-1) * X))
probability of testicular torsion =
= 1 / (1 + EXP((-1) * Y))
Performance:
• The area under the ROC curve was 0.92 for the derivation and 0.84 for the validation cohorts.
