Background: Unnecessary diagnostic testing contributes to the escalating cost of health care in the US and can cause harm to patients. Daily blood work has become a routine part of care for hospitalized adults though only a fraction of tests change diagnosis or management decisions. At academic medical centers, residents are responsible for ordering most laboratory tests. To reduce over-utilization, the reasons that residents order unnecessary tests need to be understood and the influence of local context on those reasons needs to be elucidated. We conducted a multicenter survey to investigate internal medicine residents’ perspectives on 1) the extent and frequency of laboratory over-utilization, 2) the reasons for laboratory over-utilization, and 3) the potential effectiveness of interventions to reduce laboratory over-utilization.

Methods: A 50-item anonymous web-based survey was sent electronically to all internal medicine residents enrolled in the spring of 2016 at the University of Vermont Medical Center, Beth Israel Deaconess Medical Center, Dartmouth-Hitchcock Medical Center and the University of Washington. One-way analysis of variance was used to compare the four sites on the mean level of agreement on the factors contributing to over-utilization of laboratory testing and on the effectiveness of proposed interventions. If the F-test was significant then pairwise comparison was used to determine which site differed from one another. Statistical significance was determined based on α = 0.05.

Results: A total of 460 internal medicine residents were invited to participate and 142 survey responses were sufficiently complete for inclusion (response rate 31%). Residents at all sites agreed that laboratory testing is over-utilized at academic medical centers. Residents estimated that 77% of hospitalized patients have daily blood work ordered while 49% of patients need daily blood work for diagnosis or management. While the level of agreement across sites was similar for most of the items, the level of agreement differed significantly between sites for 6 (30%) of the factors contributing to laboratory over-utilization (figure 1) and for 3 (20%) of the potential interventions to reduce laboratory over-utilization (figure 2).

Conclusions: This study adds to the literature on resident perspectives of laboratory over-utilization and reveals that the driving factors and effective interventions may differ between sites. Despite a recent national focus on high value care, residents continue to perceive significant over-utilization of laboratory testing. Understanding these perceptions helps to identify common drivers of over-utilization and effective interventions but also to develop interventions that address local barriers to change.