Evidence-based Clinical Decision Support

The impact of clinical decision support in pre-analytical, analytical and post-analytical testing.

Although laboratory services account for less than 3% of healthcare spending (and less than 2% of Medicare expenditures), they influence 60-70% of all critical medical decisions.1,2 Yet, the rapid pace of laboratory innovation and the ever-increasing breadth and depth of medical knowledge has led to knowledge gaps among the clinicians responsible for ordering these tests.

For example, a CAHG survey of physicians (oncology, cardiology and primary care) demonstrated that physicians have limited knowledge of genomic medicine-with only 8% of respondents answering as “very familiar,” 51% as “somewhat familiar” and 30% as “not very familiar.”3 However, of this group studied, nearly 9 in ten physicians stated that genomic-based medicine will have “some” to “great” influence on medicine. Additionally, only 16% of survey respondents reported that they had received training in genomics-based medicine in medical school.

Similarly, a study of family physicians determined that physicians order tests for 30% of patients; yet, in approximately 15% of these cases, the physician claimed a lack of understanding about the ordered test and 8% did not understand the results.4

Furthermore, studies suggest a wide variation in test ordering practices for similar indications.5,6 In regards to test utilization, a study by Zhi et al, suggested that the mean over- and underutilization rates for laboratory testing are 20.6% and 44.8%, respectively.7 Factors that may explain the ordering pattern disparity include the lack of knowledge of test characteristics and inaccurate interpretation of results.5,8,9 Additionally, rapid advances in diagnostics make it challenging for clinicians to stay up-to-date with the most effective testing strategies and algorithms for all areas of laboratory testing.5,8

The advent of computer-based test ordering and resulting has allowed the provision of clinical decision support (CDS) to clinicians. Just as laboratory testing can be divided into the stages of pre-analytic, analytic and post-analytic, CDS can be applied at each of these stages.


Pre-analytic, or at the time of the order, through computerized physician order entry (CPOE) represents a prospective approach to clinical decision support.

Massachusetts General Hospital, in addition to the creation of ordering guidelines, has proposed using a laboratory test formulary for reference lab testing, utilizing a color-coded scheme. “Green” tests are open to all specialties; “yellow” tests are privileged and ordered only by specialists or under approval from a specialist; and “red” tests are not recommended for clinical use and require pathology approval.10

A two year study from the Cleveland Clinic showed that when a CDS tool was used to reduce duplicate testing, over 11,000 duplicate tests were prevented—leading to savings of $183,586, and no adverse effects were associated with this intervention.11

One major healthcare insurer, United Healthcare (UHC), is currently conducting a pilot laboratory benefit management program. The pilot program, launched in October 2014 for outpatient laboratory services, ordered providers for fully insured members in Florida. In this case, the CDS is provided at the time of order and leads the physician or their designee through a series of questions to determine if the test order is consistent with professional society/governmental guidelines. Some examples of tests addressed under this program include: BRCA1/2 testing, HIV viral load, gynecological pap testing and Chromosome SNP Microarray.


In the analytic phase, CDS may include reflex cascades or advanced “smart” algorithms. Reflex cascades are branching test pathways, which are followed to a point where a diagnostic decision can be made. This type of testing is contrary to a “shot-gun” approach where a panel of tests is ordered and all tests in the panel are performed, regardless of the results. A major advantage to the use of reflex cascades is that, if patient results come back abnormal, the ordering clinician does not have to know which esoteric test to order for follow-up. Moreover, all testing is performed on the original specimen, saving time and sparing the patient the inconvenience of return visits for additional phlebotomies.

Large reference laboratories like ARUP, Mayo, LabCorp and Quest have extensive libraries of reflex cascades as ordering options. For example, at the Colorado Coagulation Laboratory, reflex cascade testing allows for a targeted approach to identify bleeding and clotting disorders like von Willebrand disease (Figure 1).


Clinical decision support can also be provided at the time of result reporting. As with pre-analytic testing, compliance with professional/governmental guidelines can be bolstered in the post-analytic stage. One recent of study of 12,353 stage 3 and 4 chronic kidney disease (CKD) patients compared to 42,996 matched controls found that a post-analytic CDS system improved physician adherence to guidelines with respect to timely monitoring of CKD.12 Not surprisingly, the CDS impact was greater for primary care physicians compared to nephrologists.

Finally, UpToDate, (an evidenced-based clinical decision support resource covering 24 medical specialties in depth), in conjunction with LabCorp, has developed UpToDate Advisor for LabCorp, a CDS resource that is specifically designed for clinicians interpreting laboratory test results. The CDS resource provides clinicians with laboratory test-based interpretations (monographs) intended for the use at the point-of-care.

These monographs are automatically linked to a result based on the patient’s demographics and the analyte that was tested (or provided in a library of monographs that can be searched by keyword). Through these, clinicians are guided to appropriate follow-up options, any available supplemental tests or other diagnostic measures. At the time of this writing, over 200 monographs are currently available and additional monographs are being added.

The Value of CDS

The availability of robust information technology, coupled with accessible evidence-based medical research, now allows laboratorians to provide added value to our services via CDS at the pre-analytic, analytic, and post-analytic stages of testing. Evidence is now accumulating that CDS provided this way helps to fill knowledge gaps among clinicians, guide testing per recommended guidelines and provide efficient and cost-effective testing. Additionally, CDS has the potential to improve outcome measures, such as ACO measures, HEDIS Scores and STAR Ratings, and to support appropriate HCC (Hierarchical Condition Categorization) coding.


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