[Differential diagnosis of jaundice by combined noninvasive diagnostic means using a logistic discriminant analysis]

Using a logistic discriminant function we retrospectively evaluated the diagnostic value of laboratory features and abdominal sonography in 70 patients with jaundice. 18 patients had an extrahepatic obstruction of the common bile duct (EHO), 22 patients had metastatic liver disease (MLD) and 30 patients had an infectious or toxic hepatocellular disease (HCD). The sensitivity resp. specificity of the 5 laboratory values AP, GGT, GPT, GOT and bilirubin was 22% resp. 90% for diagnosing EHO, 82% resp. 79% for diagnosing MLD and 67% resp. 68% for diagnosing HCD. The diagnostic value determined by their Chi2-value was AP greater than GPT greater than bilirubin greater than GOT greater than GGT. An undoubtedly dilated common bile duct was seen in 56% of the patients with EHO and in none of the other patients. Metastatic lesions were seen exclusively in 81% of the patients with MLD. No distinct sonographic sign could be found for the patients with HCD. The combination of AP, GPT and bilirubin with the result of abdominal sonography in a logistic discriminant function led to a correct a posteriori classification of all patients. Using a mathematical classification model jaundiced patients can be diagnosed on the basis of noninvasive methods alone and invasive procedures should be restricted to therapeutic interventions.