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Navigating the Patient-Directed Test Request

As a healthcare provider, you have likely encountered a patient requesting a commercially-available laboratory test to assist in diagnosing a particular disease.  Over the past several years, clinical laboratory testing has emerged as one of the fastest growing segments of healthcare, and while a significant portion of this market is composed of hospital labs, independent labs make up a major portion of this market in the United States.  Some commercially-available clinical tests are marketed to patients with severe and disabling symptoms and include inflated claims regarding the clinical utility of the tests.  It can be difficult for clinicians to effectively navigate a patient’s understandable and yet sometimes misguided request to undergo testing without clear guidelines, further complicating an already complicated situation.

Filling in medical record

A recent article by PLUGS (Seattle Children’s Patient-centered Laboratory Utilization Guidance Services) highlights how clinical test review can effectively address and avoid unnecessary lab testing.1 The article provides a case study where a psychiatrist requests the lab to evaluate a PANS/PANDAS autoantibody panel developed by a commercial lab and a framework for how the request was handled.  The lab uses a three-step approach to evaluate the commercial lab test:

  1. Do the Homework
  2. Provide Support
  3. Make a Policy and Procedure for Future Requests 

The authors recommend performing a thorough review of diagnostic guidelines, peer-reviewed literature and internet searches of important websites and similar tests to “do the homework” and determine the utility of a clinical test.  One simple indicator of a test’s utility is the presence of the test in a diagnostic guideline provided by a reputable society or policymaking body.  In the absence of this evidence, the authors suggest turning to peer-reviewed literature to find studies from sources other than the commercial lab that developed the test to validate the test’s utility.  In the case of the PANS/PANDAS autoantibody panel, the single study from an independent source contradicted the results of a study conducted by the inventors of the panel.2,3 The independent study found that both control and PANS/PANDAS patients tested positive for the autoantibody panel at nearly identical rates and that the test correctly detected PANS/PANDAS at a rate no better than random chance.  Additionally, the lab could not find any other commercial laboratories offering a similar autoantibody test for the diagnosis of PANS/PANDAS.  The authors also note that searching for a commercial test on the Choosing Wisely (www.choosingwisely.org) and Quackwatch (www.quackwatch.org) websites can also be helpful in determining the clinical utility of a test.

It is critically important to effectively communicate the merit of a clinical test to your patient.  When a patient approaches you about a test, the authors recommend you provide support and communicate the following points to your patient, with the assistance of a laboratory stewardship team if needed:

  1. Share your organization’s standards of providing patient-centered evidence-based care.
  2. Clarify the distinction between analytical validity and clinical utility of a test.
  3. Explain your organization’s lab stewardship program and how tests are reviewed.
  4. Postpone sample collection.

Once the clinical utility of a test or testing laboratory has been established, the authors recommend creating a facility-wide policy and procedure regarding future requests for the test or laboratory to increase consistency and support providers.  In the case of the PANS/PANDAS autoantibody panel, the clinical lab banned the use of the test and added the panel to a list of tests that have little to no clinical utility.

A significant portion of the growing clinical laboratory market is composed of commercial laboratories, some of which will continue to develop and market questionable tests like the autoantibody panel outlined in our case study.  Additionally, direct-to-consumer lab testing continues to provide information to patients that may or may not be clinically useful.  In light of this, the focus on patient-centered, rather than patient-directed, healthcare is more important than ever.  Kailos Genetics provides genetic testing panels based on robust, peer-reviewed research to equip physicians with test results that demonstrate true clinical utility.  Our laboratory employs next generation sequencing techniques to identify gene mutations and analyzes each mutation to determine changes in protein functionality.  At Kailos, we are allied with both patients and physicians to provide the future of patient-centered, personalized healthcare.

2Hesselmark E, Bejerot S. Biomarkers for diagnosis of pediatric acute neuropsychiatric syndrome (PANS) - Sensitivity and specificity of the Cunningham Panel. J Neuroimmunol 2017;312:31–7
3Singer HS, Mascaro-Blanco A, Alvarez K, et al. Neuronal antibody biomarkers for Sydenham’s chorea identify a new group of children with chronic recurrent episodic acute exacerbations of tic and obsessive compulsive symptoms following a streptococcal infection. PLoS One 2015;10:e0120499.