COMBINED SERUM AMYLASE AND LIPASE DETERMINATIONS FOR DIAGNOSIS OF SUSPECTED ACUTE-PANCREATITIS

Serum amylase and lipase measurements are often used to diagnose acute pancreatitis. This study addresses the question of whether it is adva ntageous to order serum amylase and lipase tests simultaneously. We ev aluated performance of the two tests separately and in combination thr ough a retrospective study of patients for whom both amylase and lipas e determinations were ordered. Initial analysis of test performance wa s conducted with a uniformly applied criterion based on determination of optimal sensitivity-specificity pairs. Individual tests and combina tions of tests, including the ''AND'' and ''OR'' rules and discriminan t functions, were examined. Only the discriminant approach demonstrate d better performance than the lipase test alone. This finding was subs equently confirmed by logistic regression analysis. We conclude that o rdering both tests simultaneously can be advantageous in diagnosing ac ute pancreatitis when a bivariate approach is used; however, this must be weighed against the difficulties associated with clinical implemen tation of such approaches.