A New Meaning to "Getting Tested"

On August 16, 2016, the Microbiology Devices Panel of the Medical Devices Advisory Committee of the US Food and Drug Administration (FDA) met to discuss the approval of over-the-counter (OTC) diagnostic tests for Chlamydia trachomatis, Neisseria gonorrhoeae, and pathogens associated with upper respiratory tract infections such as influenza and Group A Streptococcus.¹ At present, with the exception of OTC HIV and hepatitis C tests, there are no other OTC diagnostic tests for infectious diseases commercially available in the United States. The approval and subsequent availability of these tests could be the precipitating event for a more comprehensive antimicrobial stewardship effort in the community setting; however, making these tests immediately available to the public would not be without challenges.

Much of the discussion at the FDA advisory meeting highlighted the advantages and disadvantages of such tests from a public health perspective. The most appealing benefit is the potential for these tests to curb inappropriate antimicrobial use with an obvious impact on antimicrobial resistance. The issue of resistance has become a nearly universal priority, especially given the recent “Get Smart” initiative from the Centers for Disease Control and Prevention² and the executive order from the White House to combat antimicrobial resistance.³ What should be emphasized is that the introduction of these tests does not appear imminent, and given the conceivable shortcomings associated with each test, perhaps rightfully so.

The challenges alluded to above include issues with global and patient-specific implementation of the tests, faults associated with the accuracy of the devices, and accessibility. Without question, if these tests became available within the next week, they would almost certainly fail to yield a decrease in healthcare expenditures, and might actually lead to the opposite outcome. For example, if the test is used by the patient, would the provider rely on that finding, or conduct a repeat or confirmatory test? Furthermore, if the patient called the provider and reported their finding, would the provider not inquire more and simply prescribe? This would inevitably widen the chasm between appropriate use and inappropriate use in the community/outpatient setting; implementation and communication are critical for these tests to provide benefit.

The challenges of utilization span not only across healthcare but also down to the individual patient. Correct execution of the test might also be patient-specific, as simply using the device incorrectly could affect the result. A Group A Strep device was introduced in 1989 but approval was ultimately denied citing risks associated with inappropriate sample collection. Patients must also understand how to interpret the findings of the test.

The tests themselves might not be without inherent limitations as well. It remains to be seen what the sensitivity and specificity of each test will be, which could create problems for patients and providers alike. For example, the OTC HIV tests require antibody formation which typically takes between 3-6 weeks, and thus patients might interpret this as a false negative if they test too early, leading to obvious public health ramifications. False positives are likely to lead to unnecessary antimicrobial therapy and subsequent unwarranted therapy, whereas false negative results might ultimately create a greater burden on the healthcare system.

Finally, the patients who might gain the most benefit from self identifying sexually transmitted infections may not have access to these tests let alone treatment, either due to cost or stigma. The HIV and HCV tests have been marred by this issue to some degree as well. This segues to the question of whether these devices will be truly available OTC or available at the discretion of a pharmacist. Regardless of this decision, the role of the pharmacist could certainly be impacted, as pharmacists would have a critical role in triaging patients appropriately as well as in determining which patients may derive benefit from using these tests.

Despite the possible short-comings and details that still need to be worked out, these tests have the capacity to foster collaboration between pharmacists and physicians and ultimately provide meaningful benefit to patients. Point-of-care testing is already being integrated into patient care in many community pharmacies and thus the infrastructure is in place for these tests to also be successfully integrated. While the discussion is still in its infancy, it is difficult not to be “cautiously optimistic” about their potential.

David Cluck, PharmD is an assistant professor in the Department of Pharmacy Practice at East Tennessee State University, Gatton College of Pharmacy. He joined the college after completing a specialty residency in infectious diseases at Wake Forest Baptist Medical Center. Dr. Cluck maintains a clinical pharmacy practice in infectious diseases at Johnston Memorial Hospital in Abingdon, VA as well as a weekly outpatient HIV clinic with the ETSU HIV Center of Excellence. He is an active member of ACCP, IDSA, SIDP and AAHIVM.

References

1. US Food and Drug Administration. FDA executive summary: over-the-counter diagnostic tests for the detection of pathogens causing infectious diseases. FDA website. www.fda.gov/downloads/AdvisoryCommittees/ CommitteesMeetingMaterials/ MedicalDevices/MedicalDevicesAdvisoryCommittee/MicrobiologyDevicesPanel/ UCM515522.pdf. Published August 16, 2016. Accessed September 18, 2016.
2. CDC. Get Smart: know when antibiotics work. CDC website. www.cdc.gov/getsmart/community/index.html. Updated April 2015. Accessed September 18, 2016.
3. Obama B. Executive Order -- Combating Antibiotic-Resistant Bacteria. Washington, DC: Office of the Press Secretary, The White House; 2014. https://www.whitehouse.gov/the-press-office/2014/09/18/executive-order-combating-antibiotic-resistant-bacteria. Accessed September 18, 2016.