LAUSR

IMPORTANCE Reducing inappropriate blood tests has been highlighted by Choosing Wisely as a key area of focus. Computer physician order entry is one modifiable contributor, but little is known about how computer ordering compares to paper methods when it comes to low-value laboratory testing. OBJECTIVE To determine which method of order entry is associated with a greater amount of appropriate lab testing. Furthermore, to identify ordering patterns for more targeted interventions in future. DESIGN We conducted a retrospective observational cohort study of inpatients discharged at two hospitals (one site uses paper order sets, while the other uses electronic order sets). SETTING General internal medicine wards at two Canadian teaching hospitals. PARTICIPANTS At site 1 (electronic orders), all general internal medicine discharges from May 2015 and February 2016. At site 2 (paper orders), all general internal medicine discharges from April 15, 2015 to May 26, 2015. MAIN OUTCOME(S) AND MEASURE(S) Main outcome was the percentage of inpatient discharges at each site with orders for daily laboratory tests for three days on admission. Secondary measures include proportion of tests with appropriate indications and rates of discontinuation of daily laboratory tests. RESULTS We reviewed 395 discharges with a mean patient age of 69.5 ± 18.9 years and mean length of stay of 12.1 days. Daily laboratory tests were more common with paper orders (site 2) compared to electronic order sets (site 1) for complete blood count (CBC) (90.8% vs. 68.5%, p < 0.001), electrolytes (93.8% vs 71.5%, p < 0.001), and creatinine (93.8% vs 70.0%, p < 0.001) testing. However, paper orders for daily laboratory tests were more often appropriate, both in CBC (76.3% vs. 38.9%, p < 0.001) and electrolyte/creatinine (80.3% vs 44.2%, p < 0.001) testing. Discontinuation of daily labs occurred more often with paper orders (35.4% vs. 6.7%, p < 0.001). CONCLUSIONS AND RELEVANCE Compared to written orders, daily laboratory testing using electronic ordering was associated with higher rates of inappropriate indications and lower rates of discontinuation. Our results support interventions aimed at ensuring electronic order sets incorporate appropriate indications and a mechanism for discontinuation of daily lab orders. Further studies aimed at understanding how the process of completing paper or electronic orders influence appropriateness of daily laboratory orders are needed to further minimize inappropriate testing.