Superfluous Amylase/Lipase Testing at a University-Affiliated Teaching Hospital: A Retrospective Review

Background: The combination of amylase and lipase tests for diagnosing acute pancreatitis is not better than a lipase test alone; however, both tests are commonly ordered simultaneously. Further, although no data indicate usefulness of monitoring changes in elevated amylase and lipase levels, the tests are often ordered multiple times during the same clinical encounter. Methods: We retrospectively reviewed all amylase and lipase tests performed at a university-affiliated teaching hospital during a 6-month period. We considered amylase and lipase results diagnostic if they were >3 times the upper limit of normal and borderline if they were ≤3 times the upper limit of normal. During a single clinical encounter, we considered amylase tests superfluous if ordered simultaneously with lipase tests or repeated after diagnostic results, questionably superfluous if repeated alone, and nonsuperfluous otherwise. Lipase tests were considered superfluous if repeated after diagnostic results, questionably superfluous if repeated after nondiagnostic results, and nonsuperfluous otherwise. Results: In this study, 3,502 patients had 8,801 tests (4,926 lipase, 3,875 amylase), 4% of which were diagnostic and 10% borderline. Of the 8,801 tests, 45% were superfluous and 9% were questionably superfluous. Nonsuperfluous testing was less frequent (P<0.0001) in the intensive care/stepdown units (22% of 748 tests) than in the emergency department (54% of 6,000 tests) or other settings (31% of 2,053 tests). Among 3,545 simultaneous amylase/lipase tests with nondiagnostic lipase results, 0.6% amylase results were diagnostic. Of the 190 lipase tests repeated after nondiagnostic lipase results, 12% were diagnostic. Conclusion: Superfluous amylase/lipase testing in one teaching hospital is substantial, suggesting significant potential for reducing healthcare costs without compromising the quality of care when evaluating patients for acute pancreatitis.