Cost and turn-around time display decreases inpatient ordering of reference laboratory tests: a time series.

Objective: Reference tests, also known as send-out tests, are commonly ordered laboratory tests with variable costs and turn-around times. We aim to examine the effects of displaying reference laboratory costs and turn-around times during computerised physician order entry (CPOE) on inpatient physician ordering behaviour.

Design: We conducted a prospective observational study at a tertiary care hospital involving inpatient attending physicians and residents.