Superfluous amylase/lipase testing at a tertiary care hospital: a retrospective study

BACKGROUND: Measuring both serum amylase and lipase in the setting of acute pancreatitis is not recommended and monitoring changes in amylase and lipase levels after diagnostic results is of little added value. The extent of the two types of superfluous amylase/lipase testing at our institution is unknown. OBJECTIVE: Explore the extent of superfluous amylase/lipase testing. DESIGN: Medical record review. SETTINGS: Tertiary care, teaching hospital. PATIENTS AND METHODS: We retrospectively reviewed all amylase and lipase tests performed over a recent 12-month period. Amylase tests were considered superfluous if they were ordered with lipase tests at the same time or if they were repeated after diagnostic amylase results. They were considered questionably superfluous if they were repeated alone after non-diagnostic amylase results. Lipase tests were considered superfluous if they were repeated after diagnostic lipase results and questionably superfluous if they were repeated after non-diagnostic lipase results. MAIN OUTCOME MEASURES: Number and percentage of lipase and amylase tests that were superfluous or questionably superfluous. SAMPLE SIZE: 23 950. RESULTS: Superfluous testing was identified in 30.6% of 23 950 amylase/lipase tests and questionably superfluous testing in 12.4%. Of the 7330 superfluous tests, 94.8% were due to simultaneous amylase/lipase testing and 5.2% to repeated lipase testing after diagnostic results. The rate of superfluous and questionably superfluous testing was significantly higher in the inpatient setting compared to emergency department or outpatient settings (P<.0001). Of the 6483 amylase tests obtained simultaneously with non-diagnostic lipase tests, only 36 (0.6%) showed a diagnostic result. Furthermore, only 0.7% and 3.6% of amylase tests that were repeated after normal and borderline results, respectively, were diagnostic and 1.1% and 9.3% of lipase tests that were repeated after normal and borderline results, respectively, were diagnostic. CONCLUSIONS: About one third of amylase/lipase testing appears to be superfluous, mainly due to simultaneous amylase/lipase testing. Since only 0.6% of simultaneous amylase/lipase tests showed diagnostic amylase with non-diagnostic lipase levels, quality improvement initiatives should be directed at reducing this low-value practice. Repeating amylase/lipase tests following normal results is of little value. LIMITATIONS: Clinical notes and imaging studies were not reviewed.