Use of a microcomputer in the assessment of diagnosis and risk in obstructive jaundice.

A series of multivariate analyses have been carried out in 49 patients with obstructive jaundice and three indices have been derived which help in the assessment of risk and the planning of investigation and management. The k-value, a measure of endogenous bilirubin clearance, is affected by cholangitis, alanine aminotransferase, pre-intervention bilirubin levels and the patient's sex. It has similar strength to the antipyrine clearance test in predicting morbidity and mortality. The mortality discriminant index is obtained from creatinine level, serum albumin and a score for cholangitis, and has an overall accuracy of 95%. The malignancy discriminant index depends on age, cholangitis score, creatinine level and gamma glutamyl transferase, and has an accuracy of 84%. All three indices have been programmed into a commercially available spreadsheet on a small microcomputer, and are automatically and rapidly available as soon as standard biochemical and clinical measurements have been entered.