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Optimal Utilization of Laboratory Testing

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Published: November 2011

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Appropriate laboratory test utilization provides important information for the diagnosis, treatment, and management of patients. Increasingly, laboratory professionals are called upon to provide guidance in test utilization management. Efforts should be evidence-based with a clear rationale for testing, including the judicious use of protocols and algorithms. This is an opportunity for laboratories to work cooperatively with ordering clinicians to accomplish this goal.

Presenter: James S. Hernandez, MD, MS

  • Medical Director of Laboratories and Chair of the
    Division of Laboratory Medicine at Mayo Clinic Arizona.
  • Assistant Professor of Laboratory Medicine and Pathology at Mayo Clinic.

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Welcome to Mayo Medical Laboratories' Hot Topics. These presentations provide short discussions of current topics and may be helpful to you in your practice.

Our presenter for this program is Dr. James Hernandez, Medical Director of Laboratories and chair of the Division of Laboratory Medicine at Mayo Clinic in Scottsdale, Arizona. Dr. Hernandez is also an Assistant Professor of Laboratory Medicine and Pathology at Mayo Clinic. Dr. Hernandez will discuss misordered tests and working with your medical staff to improve and optimize test utilization patterns. If you have any questions, please email us at mmlhottopics@mayo.edu. Thank you Dr. Hernandez.

Thank you, Sharon, for that introduction.


Today's objectives are several. First is to define some of the most inappropriately ordered tests and the process of working with your medical staff to improve test utilization patterns. Secondly, I'd like to describe the use of algorithms to assist in rational test selection. And finally, I'd like to provide some suggestions to optimize test ordering patterns in your own laboratory.

Assumptions to Forego

Here are some assumptions to forego. A lot of us think that doctors are comfortable ordering most tests and this is actually not true. The number of tests is exploding—no one can be proficient in all areas. Believe me, I do this every single day and I have to look up tests every single day. There are thousands and thousands of tests. Secondly, is that experienced physicians need less help in ordering and interpreting tests compared to younger colleagues. This also is not true. All physicians have gaps in their knowledge. The gaps are growing because of the number and the complexity of the tests. And finally, some think that physicians will get upset it you offer help but this actually isn’t true either. If approached as a respected colleague, most physicians welcome your help.

Roger's Adopter Categories Based on Degree of Innovativeness

This is Roger's adopter categories based on the degree of innovativeness. I'd like to show you this slide for this reason, all of your medical staff will fit into 1 of these categories. They will either be innovators, 2 and a half percent or early adopters, 13 and a half percent. Most will be early majority or late majority in adopting tests and 16 percent will be laggards. I like to call them traditionalists. The innovators are going to be at the leading edge of advancing tests. Early adopters pick up these tests but notice that most will be somewhere between. What you need to be cognizant of is get the support or your innovators and early adopters. Also be aware of your traditionalists among your staff and ask them why they may oppose implementation of a new test. And I'll show you some hints on how to do that.

Changes to Manual Requisitions

Here's some changes to manual requisitions for those of you who may use paper orders. We need to send the obsolete tests into the sunset and this is a picture of me riding my horse in Arizona into the sunset with some obsolete tests—single stranded DNA, bleeding time, and T3 uptake. If you have paper requisitions, you need to be supported by a policy and procedure to destroy your old requisitions. I would recommend a hunt for those requisitions to get those out of the doctor's offices so that only your most current requisition is available. Many of us are on electronic orders at this time. Regardless of whether you’re on paper or electronic, we need to eliminate esoteric tests. For example, neurogenetic testing from requisitions used in primary care. Just recently, in my own practice, someone inadvertently ordered a second order of pancreatic polypeptide. The doctor had not intended to order that but the second order showed that the pancreatic polypeptide was increased 2 times normal. Now this isn’t a very good test for screening for neuroendocrine pancreatic tumors and it took some time to unravel what this actually meant. Which probably didn't mean anything since the prevalence of the disease in this particular population of patients wasn’t very high. Now, on the other side, check test requested, you can see that these are some esoteric tests. And some academic medical centers have actually gone as far as prohibiting everyone on staff being able to identify and order every single test.

Is This Test Misused?

Now, here's a question and as you know, pathologists like food, is this test misused? The sweat chloride for cystic fibrosis in adults. Well, the literature actually supports its use, so this test is a yellow banana believe it or not. This is not an obsolete test yet.

Overused/Misused Tests: Good Literature Support

Now, let's take a look at the overuse and misused tests. There is actually good literature support to suggest that bleeding time, single-stranded DNA, Total T4, T3 uptake, thyroid testing in hospitalized patients and the Schilling test for pernicious anemia are no longer indicated. Now, what I'm talking about for thyroid testing in hospitalized patients is not patients who present to your emergency department with suspected thyrotoxicosis or myxedema. What I'm referring to instead is patients who have been hospitalized several days in your hospital and your physicians may request a test or thyroid testing. That's not the time to do thyroid testing.

Bleeding Time

Bleeding time is a quintessential example of a test that has a lot of good literature support to discontinue its use. It's best to eliminate the test completely and not substitute another test. And we believe this will work if you have a least some integration in your medical practice. If you are a completely unintegrated practice it can be quite difficult.

Now, we want to evaluate the use of the test based on the literature. Is it appropriate and useful? And this can be a role of laboratorians, medical directors, pathologists, and scientists. We want to provide education and the rational for eliminating the test. Keep in mind your early adopters. And you want to observe the ordering patterns. The ordering patterns of your physicians on your staff will let you know who the biggest users of the test are. And we would like to eliminate the test but provide assistance as needed. In our particular practice we eliminated a bleeding time but we first gave our medical staff a lot of lead time so that they would know by a certain date the test would be eliminated. We provided the rational and we also let them know that we would have questions to ask for the clinical exam and for clinical questions to ask in lieu of the bleeding time.

Anti – Single – Stranded DNA: Another Misused Test

Here's the anti-single-stranded DNA. It's another misused test. Now this one has strong literature support to say that it's non-specific and of little clinical utility in patients with connective tissue diseases. There's nothing special about this particular test, but I do want to point out this point, that there is no CAP (College of American Pathologists) proficiency testing for this particular test. So if you are currently offering tests in your armamentarium that do not have CAP proficiency. It's a good reason to look at that test as being over-utilized.

Use of Algorithms

The use of algorithms can be quite helpful. They can provide guidance and they may reduce unnecessary testing. They can lead to actual faster diagnosis sometimes physicians believe if they order everything as once. What I call spaghetti in a bowl approach. Put all your tests in a bowl of spaghetti, throw them against the wall and see what sticks. That actually could be very timely and cost ineffective. Instead if you follow a rational thorough algorithm that has been well thought out, that can help you to rule in or rule out the entity. Our test algorithms are available at www.mayomedicallaboratories.com. There are other algorithms that are locally developed that I'll tell you about later in this presentation.

Laboratory Test Utilization

Here is our site from the Mayo Medical Laboratories about algorithms and as you can see, there are 58 results starting with connective tissue diseases and going through KIT mutation and GIST testing algorithm. There's a lot of algorithms on this site and they can be quite helpful.

Thyroid Testing Guidelines

Now, here's some examples of our thyroid testing guidelines. The first is the thyroid testing guidelines.

Thyroid Function Ordering Algorithm

The thyroid function ordering algorithm starts with non-hospitalized patients without known or suspected pituitary disease and then the evaluation begins by ordering either the cascade approach, the thyroid function cascade, or each test individually beginning with the thyroid stimulating hormone – sensitive TSH. And you can see it according to the results whether you have hyperthyroid suspect, a borderline low TSH or a hypothyroid suspect. Between .3 and 5 that's indicating that no further testing is clinically indicated.

Pernicious Anemia Testing Guidelines

Next is the pernicious anemia testing guidelines.

Pernicious Anemia Testing Cascade

The pernicious anemia testing cascade, in a similar way, starts with pernicious anemia cascade and begins with testing vitamin B12. And according to the results either no further testing is performed or you can follow down that pathway to the right where there is intrinsic factor blocking antibody. It can be either positive, indeterminate, or negative. And depending on those results gastrin is performed. So that is an example of a pernicious anemia testing cascade.

Diarrhea Work Up Guidelines

Here's another very good algorithm and this is for ruling out parasitic diseases.

Parasitic Investigation of Stool Specimens Algorithm

This parasitic investigation of the stool specimen was developed by Dr. Bobbi Pritt on our staff and shows several strategies. The first is if there is watery diarrhea in a patient who has AIDS or who has contact with farm animals or is involved in outbreak of municipal water supply or day care centers, then we recommend cryptosporidium antigen and if it's positive, no additional testing is required unless the clinical picture indicates otherwise.

If you go to the middle box, if there is watery diarrhea in patients who are less than or equal to 5 years old or have contact, or they are campers or backpackers, or they are involved in outbreak in resort community or day care centers, then we recommend the Giardia antigen. And again if the results are positive, no additional testing is required.

And finally, the third box shows if the patient is a resident or visitor to a developing country or a resident or visitor to an area or North America where helminth or worm infections have been reported with some frequency, then you proceed with the parasitic examination detecting either roundworms or tapeworms or if it’s positive you will detect the organism. And if diarrhea persists despite all these tests then specific exam for Microsporidia or Cyclospora are recommended. Note that if we follow this parasitic investigation of the stool specimens, we can eliminate many of the cases of ova and parasites. So like any hospital and clinic laboratories you may get a lot of ova and parasite requests. Following this algorithm and eliminate many of those.

Obsolete Tests: Laboratory Directors' Opinions

Here's an example of obsolete tests. These are from the American Association of Clinical Chemistry, Clinical Laboratory News, in December of 2007. These are the laboratory directors' opinions. Notice that almost all will agree the LE cell test and the Schilling test are obsolete—65 and 61%, followed by the Free T4 index, prostatic acid phosphatase and Bence Jones Proteins. Notice also though, farther down this graph, you will see some even say that total amylase, AST and total phenytoin are all obsolete.

Overused/Misused Tests — Opinion

Here's another example or overused or misused tests. These are in my opinion and based on the work that I have done with Dr. Fred Plapp who has developed some wonderful algorithms in the Kansas City area. Many sed rates, most uses of CKMB in the USA, most requests for ova and parasites, any low volume tests, especially if you are running more quality control samples than patient samples and large chemistry panels except for Medicare approved panels. Occasionally, you may hear a request from some of your doctors for a SMAC 20. Those are obsolete. Routine ordering of electrolytes, you think about that, if the patient is not on anti hypertensive medications there would be no reason to be checking electolytes in most outpatients. This is simply habit. Routine use of the CBC with differential instead of a CBC and routine use of rapid strep antigen test and throat culture if your physician intends to treat the patient regardless of the results and any other time when your tests add no value in this particular situation.

Frequency of Testing

Frequency of testing is also a concern. For complete blood count, we have to ask ourselves how often it should be ordered in a hospitalized patient and is this recommendation based on high level literature-supported evidence. Sometimes, if we just get our physicians to think about their ordering patterns without even doing anything except asking the question, we can get them to think about the frequency of the testing.

Newer Tests and Panels on the Horizon

Here are some newer tests and panels that are on the horizon and these may currently be underutilized such as genomic and proteomic markers, rapid PCR and other molecular testing in microbiology and other areas, and new biomarker panels for cardiovascular disease and oncology. These currently are green bananas. They’re quickly going to become mainstream.

Hints on Improving Lab Utilization

Here's some hints on improving the lab utilization. This is probably the most important part is the process. You can all determine in your own area what tests are overutilized. But what's most challenging is how we go about approaching our physician colleagues and let them know. Well, successful lab utilization really assumes some degree of integration of your practice. In other words, you have to have a mechanism to communicate with your physicians you have their attention. If you do, then you have a better chance of improving your lab utilization. It's important to get to know your medical staff beforehand, especially the informal leaders. These would be the innovators and early adopters and recognized experts. For example, if you’re going to change your coagulation profile, one of the first things your physicians will ask you is, "What do the expert hematologists believe is the current practice?" Same thing for endocrine testing, they will ask what your endocrinologists on staff think about your suggestions. Third, you don’t have to convince every single provider on staff—only the key users of the particular test.

And lastly, data persuades and emotions motivate. By this I mean, if you could do real good data analysis based on the literature and examination of your own practice patterns. Put that together in an anonymous way, feed that information back to your physicians and let them come to their own conclusions. It's important that we realize, we've already done this in transfusion medicine for use of blood and blood products. So this is actually not very new.

Here's some other hints on improving lab utilization which is to generate data and be available to answer questions. In this situation, I would suggest you invite criticism and critique of your suggestions. For example, we just changed from BNP to NT ProBNP and we presented it to the key users of the BNP and invited criticism of our proposal. We would like to continuously give feedback to the medical staff and I continually asked our medical staff how is this change going? Next, we'd like to scrutinize our standing orders and I’m sure you’d like to do the same thing. Scrutinize your standing orders and your order sets. There may be some things like ova and parasites, other things that are built into your order sets and your standing orders that may no longer be clinically indicated. Remember, the laboratory is no longer a revenue center, in many ways it's a cost center, so you have to work with your physicians to make sure you’re ordering the right test on the right patient at the right time and for the right indication. You'd like to also scrutinize your send-out reference tests for tests that may not add value.

Interventions to Improve Lab Utilization7

And here's some interventions to improve lab utilization. This is based on the work of Dr. Michael Astion in Seattle. He and I have worked together on trying to improve test utilization. Posting guidelines on test requisitions and computerized reminders regarding timelines, they make us feel pretty good but that's pretty gentle guidance. It doesn't always help to change the practice patterns. Next, are utilization report cards similar to what we’ve done in transfusion medicine and changes to the manual requisition or CPOE – physician order entry. And if we make those changes so we make it possible so that we can guide toward algorithms or toward judicious use of tests, that can be quite helpful. Finally, if we can do as we've done in Transfusion Medicine, have utilization report cards with peer review. This is based on data mining in your own system and any clinicians as well as pathologists and scientists in the same room to do some peer review. Higher level approval or consultation may be required for some of these more esoteric tests. And finally, the strictest guide is utilization report cards with leadership review and incentives or penalties to encourage that behavior. Some academic centers have actually gone as far as forbidding some tests. Having a green, yellow, and red pattern so that everyone can order green tests, only a few can order yellow, and red are completely forbidden unless there is explicit permission to order those tests.

Algorithm for Assessing Send – out Tests

Here's an algorithm for assessing send-out tests which can also be a drain on your laboratory. First of all, is to start at the top, what’s the clinical question to be answered. And a lot of times, we laboratorians, we'd like to be as helpful as possible but we forget to ask the question—"Doctor, what are you trying to answer—what are you trying to rule in and rule out?" And there's two questions to ask in the situation. Ask, can you do the test, but more importantly ask, should the test be done according to clinical judgment and is a reliable, scientific sound, test even available. There are some very promising markers that are referenced, for example, in the National Association for Clinical Biochemistry through the American Association for Clinical Chemistry. There are some guidelines and they show some promising markers not yet ready for prime time. If we follow this algorithm to the right, if evidence based medicine, your literature review shows that no test is available or it’s not ready for prime time, you can offer your clinicians alternative tests available in your lab or alternate tests available in the reference lab if not urgent. If we follow down the left side of the algorithm, if evidence based medicine shows that a test is available and if it's urgent and you need a fresh specimen needed and it’s less that 24 hours turn around time and you need it available 365, 24, 7, then you have to ask yourself does your lab have the technical and operational capability to perform the test and if the answer may be no. But if it is yes, then you can consider setting up that test in house if you have the volume and you have the clinical need. And you have to ask yourself that if the test can be done depending on the technical and operational aspects. And technical you'd like to work with a lab supervisor and medical technologist if you’re a director. And operational, you would like to work with your administration regarding the operational flow, financial constraints, and the capital to purchase that instrument. And in the middle, if the evidence based medicine algorithm shows the test is available, and it’s not urgent or esoteric, then you could refer it to a reliable reference laboratory.

Improved Test Utilization: Assistance from Clinical Practice Committee

Here's some other hints for improving test utilization. You might consider setting up a Clinical Practice Committee. We've had this for many years in our practice and we’ve helped others set up their Clinical Practice Committee or Utilization Committees. This shows that we have general oversight of the patient care related activities in lab medicine and we really try to look at promotion of best practice—evidence-based laboratory medicine in a fiscally responsible way. We also want to make sure our decision making processes are driven by the literature in evidence-based lab medicine and pathology. For example, let's say you have several breast tumor markers and you want to decide which one you'd like to standardize in your practice, this would be a perfect example to take to you Clinical Practice Committee. If you want to get rid of some tests, for example, bleeding time, this is a good place to take that, get people to think about it, to examine the literature and to have a game plan to really get rid of that test and to introduce better, newer, more judicious tests.

Other Benefits of Clinical Practice Committee

Other benefits of the Clinical Practice Committee show practice standardization and integration and it breaks down the barriers. It's very good for residents and fellows to routinely learn how to be systems thinkers and this meets their ACGME goals for practice, practice-based learning and professionalism. And it also gives a voice of others, like the clinicians from outside the department, to let us in the lab, to hear their perspective.


In summary, the laboratory staff can help physicians in ordering and interpreting tests and can identify overused and misused tests using literature and data-based decisions. Algorithms can be very helpful to assist in test ordering to reduce unnecessary tests and to improve the time to diagnosis. And there, you can define or interventions to guide or restrict provider choices regarding lab testing. Finally, you can consider establishing a Clinical Practice Committee to provide ongoing guidance.


Here are some references that I hope will be helpful to you in your practice.

I Welcome Your Questions

And I welcome your questions at any time either through email or through phone. Thank you very much.