Locke Lord QuickStudy: COVID-19 Testing and Informed Consent

The U.S. Centers for Disease Control has stated that testing for the presence of the coronavirus is ‎essential to containing the spread of the COVID-19.  Recent FDA guidance states that test ‎manufacturers should pass along certain information to persons being tested, so that that benefits ‎and risks associated with tests are understood.  While the FDA guidance only applies to the ‎manufacturers of tests and their distributors, the FDA guidance, and the concerns that it addresses, ‎should be taken into account by anyone who performs or arranges for COVID-19 testing.    ‎

Two kinds of tests are currently available.  One is a test for the presence of the SARS-CoV-2 virus itself ‎in the nose, throat or bodily secretions (sometimes referred to as a “PCR test” or a “molecular test”).  ‎The other is a blood test that detects antibodies that are indicative of current or prior infection by the ‎virus (sometimes called a “serum test”).  The CDC initially limited PCR testing to persons who had ‎symptoms of COVID-19 and who had been in contact with other infected persons or traveled from ‎other countries.  Now both PCR testing and antibody testing are becoming more widely available for ‎symptomatic persons, healthcare workers, and at-risk populations, such as nursing home residents ‎and, under some health department standing orders, PCR testing is available for asymptomatic ‎members of the general population in certain circumstances.  Some communities have arranged for ‎testing on demand, or even community-wide universal testing at no cost to residents.  Similarly, some ‎employers are considering arranging for testing members of their workforce as part of their re-‎opening plans.  ‎

This transition from testing persons already displaying symptoms to widespread testing and population ‎screening puts a premium on the accuracy of the tests currently in use.  It also puts a premium on the ‎understanding of the test results, and the risks of misinterpretation of the results.‎

There are two measures of the accuracy of the clinical test:  sensitivity and specificity.  Sensitivity is the ‎‎likelihood that the test will reliably identify a person who actually is infected or has been infected.  ‎‎Another way to think of this is that a test with high sensitivity will rarely produce a false negative ‎‎result.  Specificity, on the other hand, is the likelihood that the test will not identify a person who has ‎not been infected as ‎being infected.  A test with high specificity will rarely produce a false positive ‎result.‎

False negative and false positive results each present their own risks.  A false negative test might delay ‎‎administration of appropriate treatment or give an individual a false assurance that precautions to ‎‎prevent the spread of the illness are not necessary.  A false positive could lead to unneeded self-‎‎quarantine, or lead to the provision of unnecessary diagnostic or public health precautions.‎

Significantly, a test that functions well in normal clinical practice to confirm a diagnosis for a person ‎‎showing symptoms will not necessarily be useful for screening purposes (that is, for testing large ‎‎numbers of persons who show no symptoms).  If a disease is rare in the population being studied (this ‎‎is called “low prevalence”) a test that is insufficiently specific may identify more false positives than it ‎‎correctly identifies true positive results.  This is not necessarily because the test is fundamentally ‎‎flawed, but because this incidence of disease within the test population is less than the margin of error ‎‎of test.  Screening large numbers of people under such circumstances could be highly misleading, ‎causing the public to incur ‎unnecessary costs or causing individuals to submit to overly restrictive ‎protective measures.  The FDA ‎has stated: ‎

We do not currently know the prevalence of SARS-CoV-2 antibody positive individuals in the ‎‎U.S. population, and prevalence may change based on the duration the virus is in the country ‎‎and the effectiveness of mitigations. Moreover, prevalence may vary widely between ‎‎locations and between different groups of people, such as health care workers, due to ‎‎different rates of infection. In low prevalence populations, which will be much of the ‎‎asymptomatic general population, the result of a single antibody test is not likely to be ‎‎sufficiently accurate to make an informed decision regarding whether or not an individual has ‎‎had a prior infection or truly has antibodies to the virus.‎

As of this date, no test for SARS-CoV-2 has been approved by the FDA. However, a number of PCR ‎tests and antibody tests ‎have been made available through Emergency Use Authorizations (EUAs) ‎issued by the FDA.  The FDA ‎also has released a “Fact Sheet for Recipients” to accompany each EUA.  ‎The FDA requires that the Fact ‎Sheet be made available on the manufacturer’s web site, and that it be ‎made available to ‎patients.  However, the FDA does not regulate health care providers that administer ‎these tests.  ‎The Fact Sheets are typically a page and a half long, and describe the purpose of the test, ‎the known ‎and potential benefits and risks of the test, and the significance of the test’s results, ‎including the ‎possibility of false positive results and false negative results.  ‎

Understanding that there are limits to the accuracy of all tests, especially when used for screening ‎purposes, several safeguards should be observed. 

‎First, anyone administering a test that is available pursuant to an EUA should provide the Fact Sheet ‎for Patients to the Individual being tested, along with a consent form that alerts the individuals to the ‎meaning of these tests and their limitations.  ‎

Second, to the greatest extent practicable, the delivery of test results should be accompanied by the ‎opportunity to obtain follow-up counseling and interpretation of the results or guidance on how the ‎subject of the test can obtain such counseling.‎

Third, if these tests are being used to make decisions in the workplace, such as fitness to return to ‎work, the limitations of the tests noted by the FDA should be taken into account.   PCR tests can only ‎detect the presence of the virus at a particular moment in time, and cannot replace other safeguards ‎for the protection of others.  Antibody tests can suggest the presence of the virus in the past, but a ‎negative result cannot be used to rule out the possibility of early infection.  All consumers of this ‎information should be aware of the limitations of both kinds of tests, and act accordingly.     ‎

Organizations that plan for their recovery and are rebuilding for the future will be better positioned for a post-pandemic world. Please visit our Adapt. Adjust. Advance. Resource Center often for up-to-date information on navigating these and other important legal considerations in the postpandemic reality.