Wang et used the ZJU Index to predict nonalcoholic fatty liver disease (NAFLD) in Chinese patients. The authors are from Zhejiang University (ZJU), Xixi Hospital of Hangzhou and Hangzhou Normal University.
Parameters from stepwise logistic regression analysis:
(1) body mass index in kilograms per square meter
(2) fasting plasma glucose (FPG) in mmol/L
(3) serum triglyceride concentration in mmol/L
(4) serum ALT in IU/L
(5) serum AST in IU/L
(6) sex (0 if male; 2 if female)
ratio of ALT to AST =
= (serum ALT) / (serum AST)
ZJU index =
= (BMI) + (FPG) + (triglyceride) + (points for sex) + (3 * (ALT to AST ratio))
Interpretation:
• An index > 38 indicates NAFLD.
• An index < 32 rules out NAFLD.
Performance:
• The area under the ROC curve is 0.81.
• 86% of patients with ZJU < 32 or > 38 were correctly classified.
The authors also used am equation to predict the probability of having NAFLD:
X =
= (0.317 * (BMI)) + (0.875 * (ALT to AST ratio)) + (0.227 * (FPG)) + (0.362 * (triglyceride)) - 10.52
probability of NAFLD =
= 1 / (1 + EXP((-1) * X))
