Daily laboratory testing for inpatients is an entrenched routine in hospital medicine, often with limited clinical utility. As such, multiple societies in the Choosing Wisely campaign from the American Board of Internal Medicine listed routine daily laboratory testing as their top five most common, unnecessary medical practices that should be questioned. Without a specific clinical indication, repetitive daily labs contribute to iatrogenic anemia, increased risks of infection, and poor patient sleep (and thus poor patient satisfaction). In addition, these repeated tests often trigger unnecessary follow-up testing.

Benchmarking analyses performed by the University of Kentucky’s (UK) laboratory formulary committee revealed that compared with peer academic medical centers, UK was devoting significantly higher resources to laboratory testing. Consequently, our laboratory formulary committee initiated several laboratory test utilization projects inspired by the guidance of the Choosing Wisely campaign. One such project, led by a multidisciplinary team of hospital medicine, pathology, and data analytics staff members, involved a 6-month quality initiative aimed at decreasing daily laboratory test orders. We sought through this initiative to achieve and sustain for our hospital medicine services a 15% reduction in commonly used chemistry and hematology tests.

Gathering Baseline Data

We started this project by collecting over a 7-month period baseline data for five chemistry and hematology panels from all inpatient hospital medicine services. These five panels included: comprehensive metabolic panel (CMP), basic metabolic panel (BMP), renal function panel (RFP), complete blood count (CBC), and CBC with differential (CBCPD).

After our initial data collection, we implemented a series of interventions. First, our team gave presentations to UK faculty and residents explaining the rationale and goals of the project. Next, we sent weekly and monthly emails to each inpatient service provider comparing his or her lab test volume with the other service teams and with the baseline average.

In addition, we gave all providers access to an online electronic dashboard through a Tableau server with filtering capability for lab test orders by service and provider. In the spirit of transparency, this dashboard allowed physicians to see for any given time period not only their own order volumes but also the volumes of their peers. Finally, we gave monthly project updates to UK’s house staff, including an announcement of the teaching team that decreased its lab test orders the most over the prior month.

To ensure the reduction in laboratory testing did not adversely impact patient outcomes, our team monitored several balancing measures including: 30-day readmission rate; mortality rate; intensive care unit transfer rates; and average hospital length of stay. Furthermore, we also normalized lab order volumes to UK’s case mix index (CMI) to control for potential differences in patient populations. A valuable reflection of the institution-wide clinical complexity of patients, CMI is the average relative diagnosis-related group weight of a hospital’s inpatient discharges. Aside from this important indicator, we used the Elixhauser comorbidity index to compare patient populations in our pre- and post-intervention groups. This index is a risk-adjustment model which categorizes patient comorbidities based on ICD diagnosis codes.

Assessing Outcomes

When we evaluated baseline practices, we found that each day on average our providers ordered 0.663 chemistry panels (BMP, CMP, and/or RFP) and 0.558 hematology panels (CBC and/or CBCPD) for a combined total of 1.22 hematology and/or chemistry panels per patient day. Over the course of the 6-month intervention period, orders of chemistry and hematology panels fell to 0.563 and 0.454 panels per patient day, respectively. This resulted in a statistically significant decrease from baseline of 15.0% (chemistry) and 18.7% (hematology) (p <0.0001). Despite this significant reduction in laboratory testing, there were no statistically significant changes in any of our balancing measures. Furthermore, neither the Elixhauser comorbidity index nor the CMI changed significantly in the pre- and post-intervention periods. Crucially, this demonstrated that the decrease in lab tests was not artificial due to a change in the severity of the illness in UK’s patient population.

Overall, this quality initiative led to a combined 16.7% reduction in orders for these five chemistry and hematology panels and saved an estimated 41.21 L in total blood volume, based on an expected blood draw of 4 mL for each hematology panel and 5 mL for each chemistry panel. We also calculated based on UK’s charge master that this project in just over 6 months avoided a staggering $1.69 million. 

All these outcomes enable us to state confidently that our laboratory formulary-driven multidisciplinary initiative successfully reduced unnecessary laboratory tests while not adversely impacting patients. We continue to monitor our progress with the hopes of sustaining these changes. We also hope to expand this initiative to other areas of the hospital, including the intensive care units. We aim to not only achieve a cultural change within our institution but also provide a model for other hospitals looking to trim unnecessary lab testing.

The author gratefully acknowledges the participation of Ben Breazile, Thai Emmerich, Andy Kelly, Jeremy Riser, Celia Castellanos, Romil Chadha, Alan Hall, Preetham Talari, and Alison Woodworth in designing, planning, and analyzing this quality improvement initiative and in reviewing this article.

S. Emily Bachert, MD, is a pathology and laboratory medicine resident at University of Kentucky Chandler Medical Center in Lexington. +Email: [email protected]