A recent Mayo Clinic study has found that many U.S. health care providers are habitually ordering a mostly unnecessary, and quite expensive, genetic test to identify a patient’s hereditary risk of venous thromboembolism (VTE). Further, if other institutions followed Mayo’s VTE test utilization example, there is significant potential to reduce costs and economic impact in this area of clinical pathology.
Venous thromboembolism is a potentially life-threatening condition when, for example, a blood clot occurs in the leg veins and moves to the lungs. Clotting can also locate in other veins of the body.
The study demonstrates that the costly genetic test, which detects the condition called activated protein C resistance (or APC-R) due to the mutation factor V Leiden (FVL), was not needed in approximately 80% of cases studied. Factor V Leiden, a mutated form of the protein human factor V, causes an increase in blood clotting. The variant can be found in both men and women.
“Factor V Leiden is the genetic basis for activated protein C resistance,” says Rajiv Pruthi, M.B.B.S., Co-Director of Mayo Clinic’s Special Coagulation Laboratory and Molecular Hematology Laboratory and senior author on the study. “It is the most common genetic risk factor for VTE among the white population . . . . About 7 out of every 100 whites in the U.S. carry this mutation.”
Dr. Pruthi adds, “Only about 10% of those who carry it will develop VTE over their lifetimes. Nevertheless, if you extrapolate even that 10% from the 7% of the entire white population, that’s a lot of people who will develop blood clots that can lead to serious complications.”
The Link between Testing and Cost Savings
Typically, for VTE, there are two tests health care providers can order: the APC-R assay, which is a more inexpensive functional test preferred by Mayo Clinic, or the FVL genetic test, which is about twice as expensive as the APC-R assay.
To analyze ordering patterns on a national scope, the study team partnered with OptumLabs Data Warehouse, a database of de-identified, linked clinical and administrative claims information, to gain access to more than 19 million tested patients. Insurance claims for these two test methods were compared (for calendar year 2013) with the Mayo Clinic Special Coagulation Laboratory database. The Centers for Medicare and Medicaid Services Clinical Laboratory Fee Schedule was then used to assign costs.
Findings revealed that physicians at other institutions were ordering the Factor V Leiden test much more often, as the only test, which contradicts how it’s long been done at Mayo.
“Back in the mid-90s, we decided to go with a functional APC-R as the initial screening test for this disease,” says Dr. Pruthi. “And if the patient result is normal, you don’t need the genetic test. If it’s abnormal, then one can go on and confirm the genetic basis with the FVL test—and the importance of that would be to determine whether the patient carries one copy of the gene or two copies.”
The cost savings come from ordering the APC-R test first. A negative result in this functional test means there is essentially no possibility the condition exists—in which case, the more expensive genetic test would, indeed, be highly unnecessary.
The Hard Numbers
Looking at the OptumLabs data for 74,242 tested individuals, 90.1% of them received only FVL genotyping, compared to a mere 2.9% who received only the APC-R profile. And 7% of patients received both. (The data did not show why each test was ordered, nor tell how many were duplicates.) Conversely, at Mayo’s Special Coagulation Laboratory, of the 1,317 tests performed in 2013, only 4.6% of patients were tested for FVL, while 95.4% of patients received the APC-R assay.
“At eye level, we were clearly using a more cost-effective approach,” says Dr. Pruthi. “But the only objective way of getting at these hard numbers was to look at the Medicaid reimbursement.”
Based on this comparison, the cost-per-evaluated individual was $83.77 in the national data from OptumLabs and only $36.38 at Mayo Clinic, with a potential cost savings of $47.39 per individual.
Besides lowering costs, reliance on the APC-R profile also reflects best practice, according to Dr. Pruthi.
“Value-based medicine is an important part of health care moving forward, and we want to show that, ‘Look, we’re doing it right. We’re providing high-quality patient care in a cost-effective way,’” says Dr. Pruthi.
Why is Mayo so successful at this? One primary reason is test control.
For example, when a patient sample comes in for an APC-R profile test, the Mayo lab simultaneously collects a sample for the FVL genetic test. “But we control, in the lab, if the genetic test is done or not,” says Dr. Pruthi. “So, again, if the APC-R result is normal, we stop any further testing. But, if it’s abnormal, we reflexively do the genetic test to confirm the genotype. We control it, and I don’t think many labs do that.”
Dong Chen, M.D., Ph.D., Chair of Mayo’s Division of Hematopathology, and co-author of the paper, further explains: “In the reference testing market, some commercial reference labs focus on simply decreasing a test price to gain competitiveness,” he says.
“We feel differently. We believe that decreasing the ordering of unnecessary tests has the highest potential to benefit the patients and physicians,” says Dr. Chen.