Help Patients Understand Caveats of Test Results
Posted May 14, 2020: Article in Progress. We’re releasing this article ahead of our June 2020 issue to quickly provide information to our readers. The information contained in this version is based on the best evidence available to us as of the date of posting. The final version may include revised recommendations.
You’ll need to put results of lab tests in perspective...as pharmacists order, administer, and assess results of COVID-19 tests.
Expect the pandemic to spur more opportunities to expand your role...demonstrate your value...and improve patient care.
Stay on top of changing state laws and pharmacy policies...and plan for a marathon, not a sprint. Tackle practical issues first.
For example, consider what training you and your team need...if your pharmacy has a CLIA waiver and access to personal protective equipment...and how to integrate testing into your workflow.
Be ready to educate on results BEFORE you test. Explain that a positive SARS-CoV-2 test suggests an ACTIVE infection with COVID-19.
On the other hand, a positive antibody test may suggest a RECENT or PRIOR infection with COVID-19...but can’t yet confirm immunity or allow people to get back to work.
Remind patients that tests aren’t 100% accurate...and consider results along with symptoms, exposure risk, etc.
Know how often false results may occur. These details are usually in the “performance characteristics” of test package labels.
SENSITIVITY, or “positive percent agreement,” is the rate of patients who test positive...and actually DO have the disease.
For instance, if a test is 90% sensitive, 1 in 10 patients WITH the disease will have a false-negative result. Remember SnNOut...a highly Sensitive test with a Negative result rules Out the condition.
SPECIFICITY, or “negative percent agreement,” is the rate of patients who test negative...and actually DON’T have the disease.
For example, if a test is 90% specific, 1 in 10 patients withOUT the disease will have a false-positive result. Think SpPIn...a highly Specific test with a Positive result rules In the condition.
Consider the new Sofia 2 SARS Antigen rapid diagnostic test as an example of how all this impacts care. This test is 100% specific...but only 80% sensitive, so a negative test alone can’t rule out COVID-19.
Keep in mind, false results may also occur from a poor sample, testing too soon or late in an illness, viral cross-reactivity, etc.
See our chart, Point-of-Care Testing in Pharmacies, for how to get a CLIA waiver...and more specifics on tests for COVID-19.
- www.hhs.gov/sites/default/files/authorizing-licensed-pharmacists-to-order-and-administer-covid-19-tests.pdf (5/14/20)
- www.pharmacist.com/sites/default/files/audience/APhACOVID-19PharmacistsAuthority0420_rev_web.pdf (5/14/20)
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- JAMA Published online May 6, 2020; doi:10.1001/jama.2020.8259